I think it has a lot to do with the level of technical expertise for one as well as the sheer amount of accumulated knowledge among those who have been with the Amiga for years. Add to this the emotion that so many of us have for what was a golden age in computing and you have a volatile recipe for strong opinion that gets fuelled up in an environment of a split market (red camp, blue camp etc.).
I think that's about it.
Either that or it's all Franko's fault.