In my experience, there's a good and bad way to do it. There's a huge difference between bringing up negative points and whining or complaining. My rule was always - If you've got something you've got issue with, propose some action with it.
I found myself breaking the rule and complaining about East Coast weather a lot. So I then amended it to, "I hate this weather. I'm moving to Spain or California in the next year", then I took gradual steps to set myself up for it. Then I went to Barcelona, spent some time there, and now I'm in Los Angeles. "This project seems to be sucking huge manhours - I wonder if there's a way we can outsource the real grindwork here?" --> Very, very cool. "This project seems to be sucking huge manhours. I hate this. This sucks." --> Totally not okay.
I found myself breaking the rule and complaining about East Coast weather a lot. So I then amended it to, "I hate this weather. I'm moving to Spain or California in the next year", then I took gradual steps to set myself up for it. Then I went to Barcelona, spent some time there, and now I'm in Los Angeles. "This project seems to be sucking huge manhours - I wonder if there's a way we can outsource the real grindwork here?" --> Very, very cool. "This project seems to be sucking huge manhours. I hate this. This sucks." --> Totally not okay.