It depends on how you want to evaluate Jerry Jones. As an owner, Jerry is always going to deserve credit for winning 3 Superbowls. He hired the right people and put them in a position to win. I don't think Jerry has ever been criticized for that.
What Jerry has been criticized for and rightfully so is as a general manager. When Jerry took control of the team after Jimmy left, he was a horrible GM and essentially sank the team which he himself acknowledges so I don't see how anyone can dispute that.
When Jerry became an "owner" again and ceded control to guys like Parcells is when we started to experience success once again.
I think this last offseason is the first time Ive seen Jerry really have success as a GM. He made some gutsy calls that paid off and proved a lot of people like myself wrong especially in regards to hiring Wade Phillips as the head coach and hiring guys like Terrell Owens despite his background. And Jerry is too much of a gentleman to admit this but he essentially forced Parcells out. Jerry would never admit that if asked but I think he recognized after last season that Parcells was not the right person for the job and he was no longer going to abide by every decision to please Parcells (such as hiring Owens). Jerry also conveyed to Parcells that he didn't favor starting guys like Vinny and Drew. Maybe he said that to the media but all behind the scenes rumors and reports suggested Jerry wanted to bring new blood at QB. I think these decisions also made the job less appealing to Parcells and Bill was smart to recognize that he and Jerry probably see eye to eye any longer. That's not to suggest they had a falling out or any silly feud. But I think it was the difference in philosophy that made Parcells realize the Dallas job was no longer going to be the way he envisioned so he left. I think Jerry Jones deserves a lot of credit for sorta "motivating" Parcells to leave. As a businessmen, it was a brilliant move. Look at how AJ Smith mishandled the Schottenheimer situation; Norv has done a great job there but I think AJ would have preferred Cameron as head coach. When you see how smoothly Jerry got the people he wanted last season without any drama, it shows you how intelligent and skilled he is.