Uhhh...I mean, having a favorite manga/anime doesn't automatically qualify anyone as a man-child who still watches cartoons though ? Could just be something from way back, if someone were born in the 90's they could easily say Dragon Ball. My point is, you can't ask such a genuine question that people take at face value, then use the response to dismiss them as some sort of degenerated dum dum, then turn around and justify it as a "decent" thing.
You guys keep steering the argument away from the point that it's a shitty way to use a simple ice-breaker question to screen people. I'm not about to go deep into arguing about the level of interest that Japanese people or foreigners have for whatever stuff they're into.