It’s a roundabout way to mock neurodivergent people. People can flat out mock autistic traits and then be like “god redditors are the worst” and other people will agree. Of course, it’s never about the people who say these things’s use of reddit or their friends’ use of reddit. It’s not just reddit that this applies to, either. Or even neurodivergency. It can also be used more generally to be racist, homophobic, transphobic…
I’m not a huge fan of ‘narcissists’ usage here. We really shouldn’t be trying to pit neurodivergent people against each other or demonize people with a particular condition. Bullies would have been just fine…sorry about the minor nitpick because I agree with OP’s sentiment but still…