I think that's certainly fair. With that said, Walton hasn't been the same guy since his foot injury. As a freshman, he looked very capable of developing into a great point guard.
Irvin, too, has been set back by injuries. In the final 10 or so games of his sophomore year, he was playing very good all around basketball - scoring, passing, rebounding. He too hasn't been the same guy since his back injury. He's never been a high flyer, but he threw down dunks with no problem as a sophomore. Not anymore.
I think it's entirely possible neither guy was ever an NBA player, with or without injury. But both would have been far better in college, IMO. And there have been plenty of college stars (for example, Scottie Reynolds) who play at a high level but never make the league.
Right now, these two guys are what they are - good but not great players who have moments of brilliance (see Walton's seven threes and 25 points against SMU) but who are inconsistent game to game.
In terms of on court success and player development - which tend to go hand in hand - we're definitely in a lull right now. We'll find out over the next few years whether it can be reversed. I will say this, Wilson and Wagner are certainly developing before our eyes and will be a big part of a resurgence if it happens.