Because they don't like what you are saying.
It's true that there are guidelines for proper behaviour, which is absolutely right on any forum, but there is a second, more pernicious, trend on this particular sub-forum where any voice that goes against the cult is jumped on by the crowd, the poster subjected to ad hominem attacks, and - very often - the post removed.
You could attempt to argue that any dissenting voice is, by its nature of being against the majority, 'trolling' and consequently breaches the guidelines, but I'm not convinced that's a very convincing argument. Let's be honest, anyone who doesn't worship JKR or doesn't think that trans-women are simply 'men in dresses' are, in the views of many on this forum, fair game to be attacked.
Where it becomes an even bigger problem is when the worst offenders attempt to obfuscate their behaviour by claiming it is feminism. It isn't.
All you can do, short of simply staying away from this sub-forum, is to maintain your stance with grace and humility.