Right. Many communities and project teams saw a real need for an IRC replacement, whether literally or not, and Discord was the least bad choice simply by existing. And IRC channels were of course just as un-googlable without setting up a logging bot and a crawlable archive.

Not necessarily because they were scared, but probably a lot of them got banned or saw their friends get banned from Reddit, and couldn't get back on because Reddit has quite strong detection for ban evaders, so after the initial anger period, Reddit just disappeared from their mind altogether.

But they sure are upset now that Discord bans accounts based on reports to its thought police.

Both things can be true.