While true, a free and open web is generally desirable, and we'd like to keep the barriers of entry for federation to a minimum. If someone was ready to start mycool.forum, but doesn't have $500/yr to start a website, they must now wade through a garbage pile of "minimum $2,000 bid" squatted domains, weird TLDs that could declare your domain premium and charge $400,000/yr at any time, maybe even if the only thing "premium" about the name is that your website got popular, or buy a domain like themycoolforum50.com.

This might be only one managable issue, but these things add up, and the more they add up, the more facebook becomes the only website people use.