As most of the comments pointed out the problem is not with agile but rather with the tendency to only have one way to solve a problem and mostly ignore that we are individuals with rather different needs.

With respect to brainstorming I had session that worked fantastically and others that don't, and in my opinion in session that don't work there is someone that has power over the majority of the group and is simply dictating what happens in the brainstorming session.