There is a TechTalk about Closure where the speaker makes a big deal out of the whole project being done by many different developers in their twenty percent time, so yeah, they might get cut some slack and hopefully they'll be good about accepting patches to get some of these things fixed.

Gmail works pretty well, so the library can't be too horrible. I'm glad I read this, I was thinking of doing a project using the Closure library, but I guess I'll stick with jQuery.