You didn't @ me, but since your post immedately follows mine, I'll bite.
I like Kosta. I've long thought that he'd be a good fit here. In fact, his name popped into my head the minute I read about the Philly trade.
But it's simply a matter of best allocating resources.
The Kings have the best center in the NBA. They also have a very good starting power forward who can play backup center as well. Adding a third big who can stretch the floor next to Cousins or WCS would give the team an additional wrinkle that, in my (and many others here) opinion, would make Cousins even more effective offensively. As WCS improves, the minutes won't be there--sure, you can play the two centers together, but it's not working well--the Koufos/Cousins pairing is a net loss for the Kings (-3.8 points/100 possessions, to be precise). He's a very solid backup big, which is nice to have, but it's a luxury, not a core piece.
Do I think the Kings should "ship him out" just for fun? By all means, no. But I'm not so confident the Kings can "cash in on Ben" as you are. To upgrade SG, they will likely need to use surplus from another position. But from where? Many here say point guard, but with Rondo's pending free agency, dealing Collison is foolish, IMO. SF? Trading Rudy, maybe, but Casspi is more valuable to the Kings than others. PF? Good luck. That leaves us with the center position...