As much as I loved Ender's Game when I read it the first and subsequent times, I lost all respect for the man and his works after finding out what a homophobe Orson Scott Card is. He's so full of hate.
A good friend of mine discarded his entire Pratchett collection after the author came out in support of assisted suicide.
Personally, I find myself sympathetic to Pterry's morals in the case in question and unsympathetic to Card's in the case in question; but in neither case do I particularly see the point of linking the author's values and one's appreciation of their work.
However, if you really do feel that strongly, I'd suggest taking the approach my friend did - donating all of his works that you own to a library on the principle that his own personal disagreements with the author were much less important than enabling people to read books full stop.
