I mean, it's intended to be an insult because the implication is that Reddit sucks.
I personally never understood the "Redditor" insults.
Reddit is just a forum directory with an infinite feed. You can find cringey weirdos but there's also subreddits for potted plants, chess, home improvement, etc. which are pretty mundane and low drama.
I left Reddit for similar reasons, but I still use it sometimes for troubleshooting and advice in the IT/Programming space.