Having a best friend that doesn't like cats isn't the end of the world. Sometimes people just never had one and they think cats are kind of scary. But "hating" cats is a different story. Anybody who hates cats can't have much in common with a cat lover. I have had the same best friend for 22 years and although she is not as crazy as I am, she has a cat too and she loves to come visit mine and play with them. She even bought them a new laser pointer last week. One of my other friends is even allergic but she still wants to come and visit and play with my kitties.
But remember that this is YOUR friend, not your cats' friend. As long as he/she respects your decision of having cats and that you love them so much, it's OK, I think. Friends should respect one another. If they don't it is not a friendship.