Yeah, and metal is stupid simple loud music listened only by degenerates and anti-social misfits.
Sci-fi and fantasy are escapism, but so is
every god damn fictional novel ever made. I don't really understand what makes people so condescending towards fantasy and sci-fi. All fictional books have fictional elements (hence the name fiction), so if a book also has also a fictional world where it is happening, it is automatically bad? Writing a certain genre does not mean that the writing is bad. That's like saying people drawing with pencils have no talent, because the real classics are done with paint. Of course there's lot of shit, but there's lot of shit regardless of genre.
Fantasy and sci-fi also offer a great place for a writer to experiment, to create something that is not bound by the laws of reality and generally explore way more freely than other genres. Also sci-fi especially, fantasy to lesser extent, has been known to be very socially aware and critical towards the problems of our time and the problems a certain vein of development could lead. There is an actual subgenre focused on ecological issues. So that much for the "worth to society" thing.
Apparently you haven't really read fantasy or sci-fi. King is overly verbose, yes, but he isn't really a good example of either genre. Pratchett and Harrison (Harry, I presume) are mainly comedic writers*, so I wouldn't go there either, although Harrisons "Make Room! Make Room!" is a good social commentary.
There's several good authors of these genres mentioned in this thread. Go check them out. Personally I'd go for Dan Simmons and George R.R. Martin, so you could get rid of that elitist "bad prose, characterization, plot and lack of intellectual stimulation" attitude. You sound like a classical music buff who discredits rock music of any musical value because "It's loud."
*at least most of Harrison's work that I've seen/read.