My take..
Many WR's are primadonnas so none of us should be surprised by this. I actually like Crabtree or any player for that matter, who backs up what he says on the field. Would I prefer a guy who just goes out there and does the job quietly? Yes. But most of us Cowboy fans remember a guy named Michael "The Playmaker" Irvin. That guy talked a little and since he did it with a Star on his helmet most of thought it was great.
I'm all for a guy getting as much money as possible. I want more money at my job. At the same time, I think the NFL desperately needs to adopt a rookie scale just like the NBA. Rookies should sign, get in camp, and start learning. If the salary is pre-determined the player can't complain.
As far as Crabtree sitting out a year, this would be the year to do it. The UFL would love any "star" power it could get and he would easily be that league's most marketable player. Especially since San Francisco has a UFL team. If he plays great (and he should) the 49er fans are going to be livid and there will be more pressure on the team to sign him.
Last, when Dallas is drafting 32nd overall next year and he somehow slipped to the bottom of the 1st round (he won't) most Cowboy fans would want him, bad attitude and all. And if you think Jerry wouldn't draft him, you haven't been paying attention.