I was the yielding type, not speaking up, letting others take charge. In my experience, it's not always worth it, especially if you care about the thing you are working on. I went so far as to just dissociate from everything and distance myself from others. The problem is that people deserve your honest opinion if you care about them, even if it's not what they want to hear. But it's so hard to spend mental energy to listen, correct, try to prove your point... even if you succeed, they will resent you for it.