You can't judge and compare reallife personalities with online ones Wicht.

It will be far clear noticeable when you tell a strong opinion against something than when you be the 'normal' user staying on the background. People will judge you immediately on obvious behaviour. In a forum, you can rate only once. If they notice you first being negative on things, they will rate on their first judgements, apparantly negative in your case. This is nothing different than in real life, where everyone will do the same.

If they get to know you further, and know what you are capable of, what you can bring to the community/society, they will see other sides of you and can judge you far better. Since you can't vote again on a forum, their opinion is settled even when they actually changed their mind about you.

This is the reason I do not vote for a rating system, but it does not mean people here act childish. It's a human habit.