It's important to keep in mind that they live in two opposite contexts. Knuth lives a more or less "monastic" life; he practically doesn't need to deal with an

It's important to keep in mind that they live in two opposite contexts. Knuth lives a more or less "monastic" life; he practically doesn't need to deal with anybody, while Torvalds is strictly entangled with an entire community. While this of course doesn't entirely justify both behaviors, the two contexts are certainly very influential on them.