He got so much hate initially because it was shit art people would always post
posts would always revolve around temhe things he always did in his art like the moles and freckles everywhere, piercings, chromatic abberation, shit proportions, futa, the goth/punk outfits, and the edginess of his art in general. He was also a big lolcow and an unironic nazi eugenicist supporter.
Years later his art actually improved and he doesnt even do half the things people used to complain about. Shad has even improved as a person which isnt surprising since most of his edgiest stuff was from when he was 16-20. Despite this >shadman was still a fun meme that never went away and newfags turned it from complaining about objectively shitty and grotesque art into moralfagging about the few loli pics he drew.