Part of why I like it is that it's a parody of generic harem anime. Actually, I can't stand most anime because it's generic shit in some way, and Japan's "humor" is fucking stupid. That's why I like SZS; it parodies all the stupid shit other shows take seriously.
Also funny how a whole class of girls supposed to have personalities centered around a single obsession are just as DEEP and realistic as every other character in anime and manga. I don't think it's intentional, but it really shows how shitty the writing is for over 99% of all anime and manga.