The merit of fucking thin women is their flexibility. As long as they stretch before, you can usually bend them into any number of positions, and their light weight makes it easy to hold them up and fuck on the wall, off the bed, it makes things easier when they're on top.
Thicker women have more to grab, are more fun to cuddle with after, are more fun to fuck hard because it's noisier, and tend to give better blow jobs as far as I can tell, but most of the supple women I chase have full lips.
There's a lady out there for everyone.