Sure, there is certain amount of fanboism, but I wouldn't say that everybody saying anything negative about Maemo or Nokia gets attacked automaticly. For example see this thread from yesterday: Bye (for Now)
Still I think you make good point by pointing out fanboism. Negative trolling and fanboism can fuel each other and create even more noise to community. One of the reason why I think we need more selective but strict moderation, before the constructive people leave elsewhere.