I wouldnt say after years of crap booking. Two things that have to be said of Booker is that firstly he did himself no favours, with constant talks of retiring (why would WWE push someone who could be out of the business within months?).
Secondly, after he stopped bitching about retiring, he got one of the biggest pushes of his career with the King Booker gimmick, that was probably more over with the fans than even his heyday in WCW.
Granted, between joining WWE and his King Booker gimmick, there were plenty of ups and downs, but I think it was defo a 50/50 split between it being WWEs poor booking and Booker constant saying he was gonna retire.
There are many wrestlers that I would say have been wasted by WWE, Booker isnt one of them, at least not completely.