I haven't read Homestuck in a long while (yeah been meaning to catch up) but isn't one of the troll characters a spoof of stereotypical Tumblr users, particularly SJWs? (like he uses words like "triggered" and such a lot in a way that's clearly meant to be taken as a joke)

Two, actually. Kankri Vantas is a pretty scathing look at SJWs, while Porrim Maryam is a more flattering look at people who actually are reasonable debaters that argue about things that matter. Neither have any impact on the plot, however.