I think what held Mataya back is that he wasn't a career-long tournament player. But he won the Stardust All-Around, the World All-ARound in Dayton, OH and the World 8-ball (in Dayton, IIRC). All of those had the best players in the world at the time, but I'd ask
@jay helfert how big these tournaments were. Remember that we have World 14.1 Champions that only had to win against a handful of player if not less! I think if Mataya steadily played on the tournament scene from the early 70's to the lat 80's, he would have been a shoe in. As it was, he'd step out of retirement and come in 2nd at the McDermott Masters in the ... early 90's(?) and to the semi-finals on TV in the 1989 World 9-ball Open.
Personally, I think Jayson has done enough, especially if you add his Blackball World Championship in 2010, which was a WPA-sanctioned World Championship.