That's a bit harsh. If it was from a web dev company, sure. But this is from someone doing it as a hobby for the good of mankind. Yeah, the might not work for some people but it's not the end of the world. It's like saying that girl has one strand of hair out of place so I'm not going to date her. You must be fun to be around.
It takes effort to break scrolling on a website. It's not something that just happens unexpectedly, it's a conscious decision to prioritize fancy animations over accessibility.
I don't believe it is harsh given how this is a critique of the philosophy that permits a programmer to needlessly hijack user input. Especially given the context here is an OS, AND a supposedly minimalist one at that.
P.S: Last sentence probably violates HN guidelines and is just rude and unnecessary if you want to prove a point.