I'm not disagreeing with you (that a lot of people go with what's trendy or what they already know), but I wouldn't put Gilad Bracha in the list of knowledgeable people. I've seen the talk you are linking to and it's not very impressive... he sounds mostly whiny to me. In his own blog, when he writes about about functional programming or type theory, he gets called out by the people who really know about it.