I don't have a lot of first-hand context for Matz's behavior, not being a Ruby developer, but it's entirely possible, even likely, that in the context of Japanese culture, Matz's niceness would not be seen as especially remarkable. Pitting one person's "niceness" against another when they are products of vastly different cultures is questionable at best.

To most westerners, the average Japanese person is extremely polite, if not bordering on the absurd, while to most Japanese, the average westerner is, to say the least, unrefined, and Torvalds is probably downright horrifying.

Such things must be taken in their cultural context, or you can't really understand people's behavior at all.