I try to be kind, upbeat, etc in my interactions with other people, especially at work. I want to treat others well, work together peacefully, and leave the project happy. I’ve noticed that some people (particularly more curmudgeonly folks) seem to read that attitude as naïveté, and feel like they can walk all over me or treat me like I don’t know what I’m talking about. Why is that?
Reasons vary between people. It’s not important. If you want to know, ask the people in question.
Don’t think everyone SHOULD be doing it like you. If you feel like being upbeat, be upbeat. ACCEPT not everyone is but they don’t get to force their view on you either.
It’s naive to think one way is more “right” than the other.