I can't speak for anyone else, but I'm mostly taking the piss because I don't really think that demographic appeal, intentionally evoked or otherwise, actually has a tremendous amount of influence on the quality of something. Except stuff that's intended to be sexually titillating (a la Highschool of the Dead), because that particular road almost invariably sacrifices the quality of everything else for the sake of still being worse at its goal than porn.
Even then, though, you can actually get something decent out of what should by all rights be smut (just look at the Rosario+Vampire manga, especially the second part), and when it's aiming for less exclusive tropes you can get something pretty damned great even from things that are clearly intended to do nothing more than be really good at pushing a specific set of buttons (see: Azumanga Daioh, Death Note, &c.) to dispense certain types of enjoyment.
Personally, I try to avoid that sort of medium deconstruction, because seeing things in terms of demographic appeal leads to cynicism and negativity about everything much more easily than seeing things in terms of tropes. Yeah, you can go, "Well this was clearly just tailored to appeal to groups X, Y, and Z," but in the long run it seems both more fulfilling and more useful to analyze a show based on its actual qualities rather than on your perceptions of the author/studio's target audience. That's not to say that you can't also look at it from the direction of "These are the people who, generally speaking, like Thing A. Why do they like it?", but audience-driven criticism is a different animal and has fewer implied assumptions about the audience, in a strange twist.