What did Richard ever see in Kay?

I can't imagine why Richard, Lauren's stepfather, was attracted to Kay, her mother. Sally Kellerman was never a pretty woman. But even if they had cast an absolute knockout, say maybe Raquel Welch, Kay as a character was vain, shallow, extremely self-centered, bigoted, prone to emotional outbursts, thoroughly unlikeable and just plain stupid. I would have said if George the film director wants her, he could have her. I can see how Richard and Lauren would get along great. They're much alike, being kind, very intelligent, ambitious, accomplished, caring people. It's almost as if Lauren should have been Richard's daughter rather than his stepdaughter, whereas she has nothing in common with her mother. While Kay loved living in Paris, I wouldn't be surprised if she couldn't speak much French just because she disliked the filthy "foreigners" so much. And I'm pretty sure she would have had no idea who Heidegger was.