It's not just Shakur. Since Frye and Salim's class left (a class that produced 2 Pac-10 Championships, a Pac-10 Tourney Title, and Two Elite 8's) Arizona has yet to produce a career NBA player. Hassan? Marcus Williams? Ivan Radenovic? Shakur? Give me a break, Arizona has been marginal because they've had marginal players.
Arizona was elite because they produced Elliott, Buechler, Kerr, Rooks, Dele, Stoudamire, Mills, Bibby, Dickerson, Terry, RJ, Arenas, Walton, etc. and let the Shakur's and Radenovic's of the world be role players. When non-NBA players become the focal point of your squad then mediocrity is all that's to be expected. Thankfully, the recruiting is back on track as it wasn't post-Bobbi so we'll be fine.