It'd be a shame to see ep.io and Gondor go the way of the dodo bird, but what sets them apart now?
As a very happy user of some of Python PaaS services [1], there are a few reasons why I don't see myself switching to Heroku:
* These services are written by our community, for our community. The principles at most of these companies are people I've known for years. I've reviewed their code; they've reviewed mine. We'd argued, commiserated, and bought each other whiskey. They've helped shape the Python/WSGI/Django ecosystems. Their tools embody the best practices from our communities because they were there when those practices were debated and determined.
This is by no means a slight on Heroku's staff: I've met people from their team, as well, and they're wicked smart, very motivated, and highly focused on delivering an awesome product. Which it is! But as a company, Heroku is going to have to do some work to get to the same level of trust as the companies that have grown organically out of our community.
* Deploying a Python stack on Heroku is something of a small pain: there are few defaults, so you're left to do most of it by hand.
Take, for example, the bits from the Heroku/Django tutorial about configuring Celery. Not a lot of work, to be sure, but it is some work, and the result won't perform well at all (it uses a database for message transport instead of something that'll perform better). On mot Python-specific PaaS offerings, a single line in a config file (or checkbox in a web UI) gets you a fully-configured, optimized, ready-to-roll Celery setup.
I'm pretty damn good at deploying Python setups. I'm not going to use a PaaS offering unless it provides similar features to a hand-rolled setup for less work/money.
* On Heroku, I'm a small fish in a large pond. I'm the weird customer doing Python, but the bulk of their cash (presumably) comes in from their Ruby customers. Deploying Python on Heroku feels rough around the edges. A trivial example is the broken links in the Python documentation: it's no big deal, and easily fixed, but the many similar rough edges send the message that Python support is a hobby project, a sideline to the main business.
This will probably be fixed with time, I think, but again: it's going to be quite a while until I feel I'll get the same level of support on Heroku as on a tool that comes out of the Python community.
* Finally, Heroku really expensive compared to most of the Python-specific offerings. Maybe a typical Django site features more "pieces" than a typical Ruby one (???) -- a standard "smallish" site of mine will consist of Django, a task queue (Celery), a search server (Solr), a non-relational DB (Redis), and a relational database (PostgreSQL).
On Heroku, this will easily run me $100/mo. By comparison, I'm paying between $15/mo and $50/mo for sites of similar size on some of Heroku's competitors.
So all this to say: I welcome Heroku to this space; more competition is awesome. It'll really make life better for every Python web dev. But it's going to take some serious work to convince me to switch.
[1] I'm really sorry to be obtuse here, but I'm trying to be careful not to write anything that might be construed as an endorsement. As a Django core dev I don't feel comfortable playing favorites (just look at the drama that ensued when GvR had the temerity to say that he liked Django...)
Of all the points you raise, this is probably the least relevant in business terms. PaaS is about opening up platforms to all comers; one's standing in relatively insular language communities doesn't say much about one's marketability outside those communities.
He wasn't listing business reasons per se - He was listing reasons why he isn't considering Heroku. And that's a very valid reason - work with people you know and trust, rather than be a second class citizen at a primary ruby PaaS.
The hosting market is plenty big enough for more than one player - we're expanding to multiple languages, much like Heroku expanded from Ruby, which provides an ample feeding ground of old-style hosts to slowly steal business from - and there's also still a lot of room for innovation.
Heroku, as much as I like their product - and I do, which is why we started this a year ago - still has its flaws and idiosyncracies, some of which are those low-level-design type of choices where if you go the other route, a different set of people complain. You can't be all things to all people, and I don't think anyone will end up being that.
This is actually a wonderful scenario. If either party successfully grows the market, both can benefit.