Is that accurate? If I build a chat-based application, why can't I build out interfaces to various services? It may not be trivial, since some will offer features that others don't, but what's the principal problem preventing me from building a chat-based application that works over Google Hangouts, Facebook Messenger, Kik, etc. so long as they each provide an API for connecting these bots, beyond time?
Personally I'm staying away from Kik. Their MAU is low and I really dislike their constant spam.
I want to write a game server, say for Go (the game, not the language). I want to make one (or the sole) method of connecting to it FB Messenger (hypothetical, not actually doing this, and the real game server is just for my edification on learning Erlang). Yeah, this won't go very far. Once FB decides to pull a Yahoo! Games clone out they'll crush me unless I offer something sufficiently different to Go players, but outside a network of players, there's not much to offer that FB can't copy (and FB can, in fact, offer that network of players so I'm lost there too).
However, if I'm Papa Johns or Marcos Pizza or ..., FB can't shut me out. They're not going to get into the food production and delivery business. And if they did, those companies are hardly tied uniquely to FB's platform. They already have their websites, phone apps, phone numbers and other means of placing orders.
That's not true. FB doesn't have to get into the food delivery business to shut someone out.
Imagine that FB's plans come true and talking with bots on Messenger becomes an incredibly popular way for people to order pizza. A lot of people can't imagine ordering a pizza any other way. Let's say you're Pappa John's and 60% of your business comes from Messenger. Now FB has incredible leverage over you, since they effectively control a huge chunk of your revenue stream. They could decide to kick you off unless you pay them a lead gen fee, since they're generating leads for your business. Or, they could start to offer "premium" service, where message response times are slowed down unless you're a paying premium customer. Or, heck, maybe a competitor would even pay FB in a strategic partnership to kick you off. The point is that FB is set up to have incredible leverage and government-like power, and it is a very safe bet that they will do everything they can to extract taxes from the businesses that depend on them.
The bottom line is that if people are using your app because it's on Messenger, and it's not that people are using Messenger because of your app, FB has much more leverage than you do, and you are entirely at their mercy. They are very likely to take advantage of that power dynamic in one way or another.
Imagine being Venmo and trying to implement Venmo over Messenger now that FB has Payments. Likely not going to happen, and the risk any business takes jumping into a closed platform is huge (especially with FB's history). Just like all of my favorite Spotify plugins that were shutdown and replaced with either no alternative or Spotify's chosen 'replacement'.
Facebook makes money off businesses using Facebook to connect to customers. They barely make money directly off customers.
It should be expected that FB will disrupt any digital service. Be that payment (peer-to-peer, customer-to-business), access to digital media (video, image, news, music). What they won't do is replace music studios. They won't replace movie studios. REPLACE is key. They may make entries into content production, by partnership or a standalone venture, but they will not cut out other content providers. FB's network is predicated on access. Cutting off customer access to things they want is a surefire way to lose those customers. Yes, FB can make the terms more onerous for businesses, particularly competitors. But they will suffer if they push it too far and end up backing off or flailing about wildly until they fail. Most likely, they'll back off.
Amazon with Amazon Prime Video has not cut out access to different movie and television studio content just because they make their own. Same with Netflix and Hulu. If they were to do so, the value they provide to consumers would go to near-zero. There'd be no reason to subscribe to their services if you only got their (limited) content. Who wants to spend $8/month for one channel's worth of content anymore when that gets you dozens of channels with a competitor?
Same thing with news, video games, and just about anything else.
If your product is really just acting as a middle man, expect a Google or FB or Amazon to step in and screw you. Yes.
So exist on the outside. Make the games, not the game room. Make the movie, not the theater. Make the music, not the stage. Make something that the middle-man's customers want, let the middle-man do his job of connecting you to those customers (well, contract with them).
Make the video games, ideally not casual or not simply implementations of existing, public domain, games like chess or something. Make the music. Make the movies. Make the articles. FB and others will connect you to customers because that's their value proposition to customers: connecting you to the things you want. They have no need to connect you to a middle man when they can be the middle man (why would they connect you to Steam or GoG, when they can replace those platforms in short order?).
No one built a business dependent on RSS except for people in the business of building RSS aggregators. No content provider was effectively shut out of the marketplace (of content providing) by the death of Google Reader.
My point was that anyone building a business on top of Messenger that cannot stand alone is, probably, in trouble. But that's always been the case regardless of the base technology. What apps can be built on Messenger? Content delivery, potentially. Random data connectors like weather updates or where's-my-package. How can those apps stand alone against a behemoth like FB or Google or anyone else? They can't.
The point, then, is to build applications that make use of Messenger, but are not replicable by FB. Facebook isn't going to replace my FLGS. So how about I connect my inventory to an chat app so people can ask me if I have something they want? It cuts into my spur-of-the-moment sales when people come in, can't find Settlers of Catan, but see Dominion and buy it instead. But it also gives customers a better experience, and me a better understanding of what customers want (I got 20 queries for Catan this week, I should order a few copies).
Now, if I build a business which connects shop inventories to FB chat, I might be in trouble. FB can tear me apart in a heartbeat by building a small-business-inventory-chat-bot. And that's the way the world goes.
Don't build a company on Messenger that FB can replicate. Build connections to other businesses. FB won't be a bank. FB won't be a restaurant. FB won't be an Amazon. FB won't be a local small business. FB won't be a caterer. FB won't be a plumber.
EDIT: I'm tired, and this came out poorly formed. I may write another response later that's clearer once I've rested and reread this.
Twitter's API was being used to build apps that replicated and competed with Twitter's own functionality and created a conflict of interest between Twitter and 3rd party developers
There isn't much else you can do with this Messenger API other than to create channels of communication between businesses and their existing and potential customers. Those businesses likely wouldn't know how to make this themselves, so you could make a bit of money there.
This wouldn't compete with Facebook, but rather ties both customers and businesses tighter to Facebook, making FB more valuable to those businesses and and perhaps encourage them to spend more on promoting user engagement.
There'd be no reason Facebook would want to shut you down. They certainly don't want to get into the nitty gritty business of connecting chat messages to all the various ways different businesses could function.