Not him but that sounds a lot like "the evil ones are trying to corrupt people".
The answer is simpler than that. Normies are band-waggoners and money beckons people.
A lot of the /d/ fetish stuff was popular *inside* those circles and some of them were willing to pay good money for it. Remember before when geek/nerd/digital artists used to have a side gig as nsfw artists underneath different names because degenerate whales kept them afloat financially? This wasn't a huge problem back when geek was still unpopular because shame (from various directions including self-shame) used to keep everybody in check.
When geek became mainstream all the vultures started looking to exploit every avenue of revenue and normies, being the fucking lemmings that they are, hopped on popular trends, trends that may have not understood or were disgusted by but still hopped on them.