Linus is saying: "there are some people I do not like, and I will never like. But I do not want that to get in the way of being productive. We can still work in the same project, maybe not side by side. And whenever you make a mistake, I will let you know without the tiniest doubt. And you should do the same, too." I think this is clever, and allows for very diverse teams, where people are able to work together even though personally do not fit at all. People are different - let's find a way to overcome that!
Basically, Sarah is worried about the social side of running the kernel - the egos of people - and Linus is (surprisingly for a manager!) worried about the technical side, sidestepping personal issues. He just does not care if you are feeling hurt. For that, you have your mum.
For him, the only worthwhile goal is to be productive, and to communicate clearly what he is thinking. Sarah expects him to understand that she is pissed by this. In this case, the whole context makes it very easy to understand it, but being polite is very often the wrong way to make things clear. It just takes much longer, and sometimes you never realize there was a problem to start with. Since she is trying to solve this issue "politely", it will just take forever, and no solution will be reached - because there is no solution! People are not going to start loving each other just because she would like to. She is trying to create a kernel lah-lah land, where everybody is happy and at peace with each other. Not gonna happen!
At the end of the day, it just a harsh email that you get. I would say, get over it!