If you make yourself into the guy that fans want to see in a title fight, you'll get your shot.
If you step up when the company needs someone to step up, you'll reap the rewards. Without offering to fight Jones on eight days' notice, I really doubt that Chael would have gotten this shot.
But when the UFC President has a title fight fall apart at the last minute, and he calls all the contenders and says "Do you want a title shot next week? We need somebody to take the fight or the card is going to collapse", well, why should the guys who say "No, I don't want a title shot, here is my list of conditions to fight for the belt" be rewarded over the guy who says "I'll fight anyone at any time. What can I do to help promote the fight?"