The fact that you consider it porn kind of makes your point fall flat. Overhyped? That's up to the individual, but I hate that term for anything because more often than not it's used as a vague catch-all with no real meaning instead of someone being able to explain their point. It's also kind of an arrogant term to use, but that's neither here nor there. Using Michael Bay as a comparison is kind of laughable because his style of movies and BITWC do very different things, except one is a legitimate movie with depth, character development, and merit beyond the spectacle and the other is a director who deals purely in spectacle because it appeals to the common viewer and to those who claim to be above seeing them and then see them anyway just to continue the vicious cycle that they put themselves in.
BITWC is a much more interesting movie both visually and just overall than Michael Bay things specifically because of how human and true to life it is. It deals in reality and is all the stronger for it. A Bay movie doesn't and are only interesting from a very limited technical aspect; say what you will about the QUALITY of a Bay movie, the guy, when he isn't relying on shitty designs, can frame an action scene - not always as well as some who DON'T rely on CG, but better than a lot of people with similar sized budgets.
I can defend BITWC as a film because it is a wonderful character study and a coming of age story, both genres that are done often but not always well - just count the number of movies set in, say, a high school where no one acts like a teenager does and the movie is worse because of it; in a genre that plays on realism, failing to get that part of it correct is a death mark.
I feel nothing in a Michael Bay movie (again, these comparisons are pointless, as they are vastly different types of films) other than a feeling of utter boredom. I feel actual feelings from a film like BITWC because of how utterly real it feels, and you don't even have to be a lesbian to get that feeling, as it does relationships in general, especially those awkward teenage ones, fantastically.
I do think it's apt that you mention The Color Purple, though, since the point of it being named that is because of Celie has a hard time noticing beautiful aspects which is something BITWC has in spades.
But, hey, that's just my defense of the film.