No, no. You don't have to like anyone. I don't, for instance. I loathe each and every person and group of people more or less equally. Some draw more of my venom than others(I'm looking at you Westboro, Nazi apologists and Vuvuzela enthusiasts) but I find something utterly deplorable in every human being who has ever been born or will ever be born, except Freddie Mercury.... or you must like certain group(s).
The problem comes in liking X groups and placing them on a pedestal over, and to the detriment of, Y groups.
This isn't a master-class in neurochemistry or rocket science, you should be able to follow along.