When you can get talent for free -- in this case Nate Robinson in exchange for a Kenny Thomas, you have to do that. He's young, he may even help you net that starting PG in the future. You coul have moved him for a player, a pick, whatever.
Normally I would agree, but he's a restricted free agent in the offseason, so he's not really tradeable. We would have had to sign him or do a S&T, which is always tricky, and then he becomes BYC, and it gets really complicated to deal him for another year.
He would only be worth trading for if we wanted him to stick around for a while, and I'm not sure how that would work long term.
Meanwhile, Kenny's contract is about to get a whole lot more valuable, particularly on draft day.