king crimson has been around since the late 60s, and in those times played progressive rock rivaling bands like pink floyd. Sure their new stuff isnt so great, but none of the remaining members are still around if i remember correctly either.
I'm not saying King Crimson sucks, they are good at what they do. It's just more people knew about Yes than Crimson, yet this internet age has exposed more youths to Crimson than Yes. They're not as adventurous as Yes for me, yet I respect Crimson as a good progressive rock group.