I used to go to bookstores and buy stuff for the covers. Interestingly enough, I discovered that if I liked the cover I would generally like the book itself.
That was a shame. sci-fi has always been one of my favorite subjects in art. I have a huge collection of sci-fi novels many of many of which I got just for the cover art.
I think it is accepted more these days. My biggest problem is competing with the work done by the computer graphics people for the movies! Sometimes I feel like a Neanderthal who has just met a tribe of Cro-Magnons