I happen to have a definite, knock-down argument in favour of a particular semi-column free style: mandatory indentation (which also eliminates curly braces).
http://okasaki.blogspot.com/2008/02/in-praise-of-mandatory-i...
I'll grant you that's not a large scale experiment on a peer reviewed paper. But I trust Chris Okasaki on this one, and to me, his experiment counts as strong evidence against semicolons and brackets. (Specifically, semicolons and brackets are error-prone, especially for beginners.)
Now for Javascript, I'd probably write the semicolons. Because there is some ambiguity in the way we humans would parse Javascript without semicolons. But really, the root of the problem is that Javascript's syntax is suboptimal. Sure, Dennis Ritchie didn't know better at the time he wrote C, but this is no longer an excuse.
If I had a say, I'd simply write an alternative syntax with mandatory indentation. It's not hard[1]. If Bootsrap's maintainer dislike semicolons so much, he probably should do so as well. He will likely lose contributors, but someone who cannot get past a Python-like syntax is probably not someone he would want to work with anyway.
[1]: http://www.tinlizzie.org/ometa/ (Quite the tool for the job. Plus, it already features a Javascript parser you can modify.)