his maps are sort of amazingly generic and dull, the lighting is weird, the texturing is weird, there's nothing going on, no ambience
they're really boring, you see. terrifyingly bad actually
and then what's even worse is that they're so amazingly generic that people use his maps instead of making their own generic stuff and getting better as builders, because his generic stuff is not only pre-existing but exactly what they need to make their generic city RPGs or family RPs or whatever
it's sort of like afghan DM syndrome, only afghan DM isn't bad as much as it is overused