In my experience, brainstorming tends to be dominated by whoever is loudest and least coherent - the fuzzier and less thought-out an idea is, the easier it is

In my experience, brainstorming tends to be dominated by whoever is loudest and least coherent - the fuzzier and less thought-out an idea is, the easier it is for everyone in the room to agree on the broadest strokes, and have completely different understandings of how to actually get there. Try to pin them down on specifics, and you get labeled as obstructionist or otherwise "difficult".