Unfortunately, I'm away from home at present, don't have my collected data with me, and will be back in the woods with company later tonight, so I can do little to show why fg% is a poor measure. You have access to basketball-reference.com and mysynergy sports, so you can see Big Al's PPP (which takes into account shooting attempts, including shooting fouls, and turnovers but not assists) and TS%. Drawing fouls is awfully important in today's NBA.
To me there are two different points. Is Al an efficient player, and is Al a dark hole (are these the same thing, or are they different)? Another part to the dynamic is coaching. I am a firm believer in the onus being on the coach for the overall effectiveness of the defense. You can have one or two bad defensive players and still have a stupendous defense (e.g., Tom Thibodeau). How much of the responsibility does the coach take? Same goes for Scotty Brooks. Bogut's really good, but who else?