You must have very different kinds of meetings than I do. Unless you're going into that meeting with a rehearsed PowerPoint presentation, or there's a strict agenda that doesn't allow any time for exploration, I expect to hear imperfect-ideas-in-infancy. One of the reasons we have meetings is to allow collaboration to happen. It's a format for working together.

Yes, meetings vary profoundly in terms of their quality, purpose, and participation. For instance, is it a meeting of peers, or are managers in the room? If there's a large disparity of roles in attendance (e.g., junior engineers, marketing managers, and maybe one or two executives), it's different than if it's a true meeting of peers. And if managers are capable of attending those meetings without quashing collaboration, hats off to them.