I would think Linus has some form of light asperger, and when he calls someone "dick head" thats not aggression against a physical person but in this case to the fact that someone pushed code that does not build. He's to rational to mix up personal feelings against somebody and the quality of the code. The only way to get offended when Linus goes of in a rant is to think that he does.

Also maybe it's the fact that I'm Finnish too, but the best teachers from school I remember where those that valued perfection, and I don't think they raised their voice to abuse one, but to make a point...

I can still remember a computer teacher who went bananas every time someone used the carriage return in the middle of a paragraph, and physically broke of the key from the keyboard, just to show that It wasn't supposed to be used that way. Maybe some people got offended or scared, but to me it stuck, the importance between separating visual appearance and semantics...