I don't see a culture in pride about mocking people. Yeah, Linus made that statement that it's fun to poke fun at people, and sometimes he does that too much. Although, I've been the butt of his insulting jokes before, but to be perfectly honest, he has that wit about him that he can insult you and you are still entertained by it. I now look forward to the next insult that Linus gives me, that I sometimes egg him on ;-)
But really, I've seen LKML actually become much more professional and less insulting. 8 years ago it was more vicious. I've seen people get insulted for no good reason, and the insults were quite nasty. Today, and even the example someone posted here, the insults come after a lot of back and forth where no progress is made, and the developer finally gets frustrated. You can even see the frustration in the insults.
Sometimes its just that the person on the other end isn't getting the point of the developer. Lots of miscommunication. That's natural. My point is that on the whole, kernel developers are pretty good to you if you just try to make an effort, and hide your ego. The last thing a developer wants is code coming from someone that says they know better than the developer. Sure, they may know more, but it works much better if you show them benchmarks and numbers to back your work, than just saying "I'm an expert in this".