You make it sound as if WWs are somehow inherently more skilled than LWs, but the only quantitative difference is weight. Khabib is a large lw who struggles to make weight. If GSP comes down to 155, it's not unreasonable to think that at best, they're similar size, and possibly khabib would be larger. So GSP is wanting to come to a weight class he's never fought in before, to fight a man many people consider the GOAT at that weight, who is undefeated and very much in his prime. That's the opposite of cherry picking.