I laud his inititiative. If herding cats takes talent, herding documentation-averse cats must be even harder. Best to make an attempt, get buy in and feedback, and move forward. If the people at the top say "bugger off", oh well. If they say, "Thanks for starting this, let's see where we can go from here", then not only are they being decent people, but also constructive.
I think the site looks fine, as in neither bad nor awesome. Similar for the official site. Nothing special, just different.
Fine is usually more than enough since fine is usually better than 90% of what's out there. I've been reviewing design shops for a site redesign and most of them not only have less-than-fine* websites, but their clients' websites are equally less-than-fine.
* i.e. bland, uninteresting, a mess under the hood, mildly unusable, ...
Evolutionary - no fine is not enough. If you can choose between bad, fine, great - you pick great unless it's takes too much resources (time/currency/etc). In this case the constraint are "open source workload" which is quite massive nowadays - then consider a "fine" site hacked together in an hour a good solution on this problem is "not enough".
Now it seems the picked path for ruby-lang is open contribution, that is not just "fine" - it's great.
I think the site looks fine, as in neither bad nor awesome. Similar for the official site. Nothing special, just different.