No, not just due to standards-committee politics. Many people didn't like ECMAScript 4 for good reason. I read the spec. It's monstrous. I have hardly ever seen a language with so many overlapping, redundant, completely pointless language features. I'm glad it's dead and I hope it doesn't become undead one day.
http://ajaxian.com/archives/ecmascript-edition-4-brendan-spe...
http://weblogs.mozillazine.org/roadmap/archives/2007/10/open...
http://ajaxian.com/archives/the-future-of-ecmascript-3-is-4