I don’t think people hate discord as a host for some communities, but there definitely is a growing rejection of it among FOSS contributors.
It sucks as a place to store knowledge. The search sucks, it’s not indexable by search engines, and requires an account to use. As another commenter on this post said, it combines the worst parts of IRC and webforums.
There are better ways to organise a FOSS project, and people are unhappy that some projects still choose discord.
Slightly confused by your last point, about the org itself, could you expand?
This seems to imply to me that the organisation could never be “hurt” because it’s volunteer run, which I doubt is what you were saying.