I don't hate Bonner. I've actually defended him many times in the past, especially last season early on in the year when is production was quite good. But that was then and this is now.
I think where we are not finding common ground here is role and expectation. Splitter is here now, so that gives the Spurs four rotation bigs. Duncan should play 30min, Splitter 25, McDyess 20 and Blair 20. There are 96 available minutes on the front line...and that scenario would consume 95. The 5th big should only play spot duty and in situational lineups. That's why I'm saying Tolliver is a better option than Bonner. He's not as good of a shooter(he doesn't suck, as you suggest either...33% from the arc is serviceable), but he is quicker, a better rebounder, passer and at least has some upside. These are the types of thing one needs from an energy big. The fact that he could be signed at the minimum and not locked in to a long, expensive deal makes it an even easier choice.
There is no longer the same role here for Bonner...unless you are saying you want to take minutes away from Splitter/Blair/McDyess.