that may be true for the wider tech community. but the FOSS community is still driven by idealism. and that's why i am here. hackernews has a wider topic range than places that focus on FOSS only and it has a significant (but not dominant) following among FOSS enthusiasts.
basically what used to be kuro5hin and what slashdot maybe still is.
I think the zealotry is being protectionist trying to keep things fun and useful and not tainted by the need to extract a profit
if you don't see that then maybe you are not meeting the right people. those who do the work just get along fine. they are not bad-mouthing others for not doing it right.
and people who refuse to work with non-free software, that's their choice, that doesn't make them zealots. and i haven't seen any example of where that would make a community toxic.
that doesn't mean that there is no toxicity, i am sure there is. but not more than what you can find right here on hackernews.