In the Negazone you can post negative opinions safely. No one will argue with you or say they think your idea is bad. You are free to post things you don't like or think should change without fear of being drowned out by the "sycophants."
The only exception is personal attacks. Do not personally attack others here or anywhere. That includes talking about anyone that could conceivably see it, keep your complaints to the game, forum software, etc. All the unfeeling robots that won't mind being badmouthed. If you're mad at someone, cool off, read up on cognitive dissonance, recollect your thoughts.
That said, this is not a prison for contrarian beliefs, it's just the only safe space. You can post about changes you want elsewhere, but I or others will argue with you about them. This can be a good thing in its own way, as it establishes a dialogue and allows for compromise. That said, you don't always want to argue, so feel free to post here instead. If someone PMs you to argue or harass you about a Negazone post you made, report them and I'll ban them.
Official forums have a tendency of becoming hugboxes. People that like the game tend to stick around and defend it, while people that don't get tired of arguing with the pro majority and leave, causing that pro majority to become worse over time.
If someone doesn't like the game, I want to know why so I can fix it. It doesn't mean I'll make the changes they suggest (that's rule 1 of game design), but I will look into why it frustrated them and try to make positive changes. The more varied opinions and complaints I receive, the better the overall game experience becomes for everyone.
There's a cognitive bias to focus on negative opinions and ignore positive ones, which can cause you to believe that complaints are more common/oppressive than the positive ones. This is not true. Complaints make up roughly 15-20% of feedback received, and only 5% of users leave any feedback at all. Complete silence is more likely to kill a project than any amount of complaining, so I think it's important to encourage feedback. Try to encourage Negazone posts however you can, you can post to agree or relate similar experiences, or simply upvote. If you disagree, carry on. If you disagree and I end up making a change based on it that you also disagree with, then make your own negazone post, or post in a discussion thread. Nothing is permanent, everything is subject to change based on feedback, but only if that feedback is received.