I view it like the quirk replacement mod: A tool that makes reading Homestuck easier for some people with the risk of losing some of "the art."

I won't argue for the merit of any specific use of a slur in Homestuck. Except for !Future arachnidsGrip. But if we follow the pattern of slurs throughout Homestuck, it feeds into one of the work's core themes: creation as a constant process. Act 6 gives us Caliborn; the character most likely to use slurs at the drop of a hat. But unless you count "bitch" (NOTE: Does the mod count bitch as a slur) he's notably more tame than the teenagers who came before him; who happen to have grown out of the practice.

The Scratch, and Act 6 in general, is a do-over. Here's what Homestuck would be like if it began in late 2011, but with all of the lessons Hussie learned while working on Homestuck. Would the webcomic have been better if it truly didn't begin before then? No, because then Hussie would have never had the learning opportunity of creating Homestuck.