Sounded great till that point. He's putting his own nerd centric bias into it. If I'm a history guy, not a tech guy, and I want to "fork", asking me to run my own "server" or whatever is a non-starter.
TL;DR good companies make life easy for people who want it without hassle.
The difference is that you don't have to run your own server to edit or otherwise participate in Wikipedia. You don't need your own server to have a blog on Tumblr or WordPress.com.
And since Simplest Federated Wiki requires either Ruby/Sinatra or Node.js/Express, you need more than just a shared hosting account to run it, which raises the barrier to entry (though the one-click installer, or PaaS providers, help lower it again).
It may eventually be a non-issue if someone builds a "wordpress.com for federated wikis."
It's like saying I should have to know how to lay asphalt to drive on the highway.
Why? Sure, it lets you do some things that almost nothing else does, but you can usually work around them, and it imposes a great cost of both time and money. Why should one spend them?
And likewise, learning how to run a web server on the public Internet (as opposed to a toy server on your LAN) requires a huge amount of time and knowledge, in terms of learning how to use the software, secure it, keep it spam-free, keeping up with the updates and security vulnerabilities, configuring DNS, etc. And at the end of the day, it can still be taken down by the hosting/VPS provider or ISP, just like your Wordpress.com blog.
So, is it really worth it? I doubt it.