They spent the last ten years filling their stadium and appearing on national TV. They were able to recruit their full complement of top-notch football players. They were able to make it to high-profile bowl games. Most if not all of those things would have at least been interrupted for a few years by revealing what was really going on in 2001.
From a purely football standpoint, I'm not so sure they'd be better off at this very moment if they had been forthcoming back then. Penn State was struggling to win games at the time. A scandal like this would have added an additional stain on top of the losing results. Instead of bouncing back, they might spent the last decade like UCLA or Tennessee.