Warrick only got 24 mins/game on the worst team in basketball. At 27, he has essentially reached his ceiling and is a classic tweener between the 3 and the 4. You're right, he probably should be in the league as someone's deep bench guy. But the numbers don't impress me in spite of his athletic ability.
I haven't seen much of Bynum since college so I can't tell you if he "belongs". I imagine most of Bynums points came in garbage time with him going to the basket a lot.
What I do know is that there is more talented players than available roster spots. Just because a guy is talented doesn't mean he belongs in the NBA.
The "worst team in baksetball" had a better option at forward in Rudy Gay. If his ceiling is 12/5 in 24 minutes, why is he a "deep bench guy" ? I'm sure plenty of teams would love to have a guy like that. The suns, for example, could have used someone like that for years. He's also a good defender at both the 3 and 4 spots, which would have made him incredibly useful in Phoenix.
Let's make a little comparison, shall we? Diaw averaged 13/5 last year in 34 minutes. 1 more point in 10 more minutes, and in a starting role on an equally bad team. Does Diaw not belong in the league? Should he be buried on someone's bench?
Bynum's points weren't all in garbage time, as he played 14 minutes a game. Who cares if they all came with him driving towards the basket? Monta Ellis scores almost exclusively on driving, and so do a host of other NBA players.
To say that either of these guys, especially Warrick, doesn't belong in the league is ludacris, plain and simple.