Even in a small community attention can be expensive. I've worked with a number of developer groups. Within each I would eventually reach a point where people knew enough about me that I could ask what might initially seem a stupid question but often lead to some interesting discussion because I was trying to a) make sure I understood this or that assumption and b) see if some assumptions were just plain wrong.

And the group knew I wasn't just dense or playing games; I might be wrong about this or that, but I was sincere and likely had at least some insight to offer.

I'm sure there are various ways to get these same kinds of group discussion going but reputation saves a whole lot of time when trying to explore a counterintuitive idea.

Even in small groups people have lots to do, so having an "in" based on reputation is important.

BTW, I do share the OP's point about bluntness, and I've been fortunate to work with people who, after considering something I've suggested, would give a direct, matter-of-fact opinion.

But this may be another case where personal knowledge helps; most people respected each other well enough to understand that there's a difference between dumping on an idea and dumping on a person. The nice thing was that no one thought you stupid because you said or did stupid things (if your overall reputation was for general non-stupidity) and it made communication easier.