Yes, everyone is pretty technical. The author of this article (ptag) spends a decent amount of time helping the people out who aren't as well-versed in infrastructure/networking.
The custom jiggery pokery is the point. This is like telling someone to throw away their hobby car they work on over the weekends and replace it with a new electric vehicle because it'll, "Just work." The configuring things, understanding the infrastructure, that is _the point_.
Some people have just opened up their entire home networks, other people have VLANs set up and only share that VLAN with TPL. However, as written in the article, everyone knows at least a few other people on TPL and that interpersonal real life trust is what keeps people from screwing around on everyone else's networks. Everyone is also an adult.
I'm one of the people whose home LAN is completely exposed to TPL. There's an amount of "screwing around" where I wouldn't care. If you want to print an xkcd cartoon to my desk, fine, lol, a minor surprise in my day. If you print 1000 pages of dicks while I'm not home so that my paper and toner run out, that would be uncool. After years of caring about this problem, I came to believe that this kind of normative social contract cannot scale to include "everyone in the entire world," and that this kind of unwritten normative code is the only thing that makes any social space tolerable.
This kind of defeats the purpose of TPL. Part of TPL is setting up your own network segment. There's a dashboard that shows who has what working.
Part of the fun of TPL isn't just that your computer can talk to another computer, it's that you have your own setup configured form the ground up so your /24 can talk to other /24s on TPL. I 100% understand some people will not enjoy that and won't find it fun, and that is ok. Some people do enjoy learning new things about setting up infrastructure, and this scratches some of that itch.
No games are played on TPL. It's more just socializing. There's IRC and stuff, and people host weird things.
When you join TPL you get a generated LaTeX document with all your connection-specific details. That document breaks down kind of _everything_ you need to know to join, and then you're paired up with one of those primary backbone people to connect.