I don’t idolize Linus but the added context here is that the Linux kernel is a very sensitive project in many regards (don’t break user code, prioritize performance, try and do a good job security-wise etc.) and there’s a steep learning curve before participating. Linus is kind of right part of the time when he gets angry at people who never bothered to learn the basics on how to participate.
I mean, that’s like going to a job interview at NASA without having interest in physics and astronomy.
So again, the guy can be a douche but I feel such a gatekeeper is needed for a high-profile project like the Linux kernel.