The rough tone on lkml (supposedly) reflects the gap between people who want to make something that's nontrivial and used by many people and the smaller number of people who are actually able to do so. Setting yourself up as this kind of gatekeeper means you have to be non-likable towards a lot of people even if you're a perfectly nice person.
Conversely, someone can be an asshole while showing spotless behaviour to the people they meet.
I try not to learn anything about any creator whose work I admire, they will unfortunately generally disappoint.