Well the large combs are good for heat dissipation in hot climates. Kind of like an elephant's large ears. It's fun that everyone has a different aesthetic, that's why we have so many breeds of chickens to choose from! :)
I agree they are better adapted, but they just aren't as pretty IMO. Nothing like a big toothed single comb to say, "I am rooster, hear me crow!" Too bad I live in a cold state and really "should" go for pea/rose combs.