I think it's vapid, Joffrey was a a psychopath, who did heinous things, but I could jump on that wagon because the character was well written, and the actor was great, he also had running battles with Tyrion that kept it engrossing, gave Cersei more depth and made us glad of Tywin at times, even if he was clearly a 'bad' guy, they allowed at least his presence to be multi faceted, and it worked very well. Ramsey's only purpose, seems to be so he can be the dark to jon snows light, whom I also find pretty boring, at least with Roose, he added to the political intrigue, which the show runners seem to actually be openly avoiding now, just as well really, we wouldn't want to add depth and come across as pretentiousDo you not think that sometimes you need to have those extreme characters in a world where everything is purposely crossed over for the sake of it? I mean Jamie or arguments sake has had so many good and bad things thrown at him it is hard to even portray him either side of the spectrum.
for me personally, i just enjoy having at least one character so far gone off the scale that you don't need to read them. Sometimes for me, story telling just works when you don't need a backstory to it, ramsey is a evil tit, great. I don't need motivations for him, or reasonings, i can just accept it.
I think considering the general audience of the show, being to convoluted would lead the show into being a bit too pretentious for its own good