This is the dialect of /r/wallstreetbets. Apes strong together and all that jazz. To call someone a retard is a term of endearment, or a (not so) secret handshake.
(fellow gambling degenerate)
(fellow gambling degenerate)
I mean it's basically the same kind of people that turned a word that simply meant 'delayed' into a slur.
This is not an example of that though, since "retarded" is not a slur in WSB, it's the opposite.