There's a difference between having a harsh tone, being rude and being mean, so I'll go through what all three of those mean in my opinion:
Harsh tone: In my opinion, a harsh/blunt/matter of fact tone is a good thing in discussions. Often people mistake a harsh tone for meanness. Stefan for example makes very blunt and factual posts when he disagrees with people. This is often mistaken for meanness.
Rude: Rudeness is the most common form of "meanness" on the forum, and that's where I would put the examples of posts directed at new people to the forums. I think that pointing people towards the OAQT is good, but often people do it in such a way as to try to make the OP feel stupid. This is rude.
Mean: Actual meanness is not something you see often, and I don't think it's a big problem on the forum. There is occasional bullying, but the mods do a good job of stamping that down.
As to your complaints about the responses to your thread...
The second page has literally nothing mean or negative on it.
The only thing that fits into one of my three categories is
this, and that is just harsh, not mean. Stefan was merely pointing out some gaps in your logic.