The thing is, where is the development going to come from?
As a 25 year old, he needs legit NBA game time, not practice.
The Cavs signed Jefferson who at least for this year is a likely better fit and performer at backup SF than KP. And they did the for under 1 million dollars.
So are they going to bring in a guy(via waiver claim), pay him $5 million plus the huge associated tax payments, and not really have a slot for him on the court, unless there is an injury?
Also, if they were to claim him, I'm pretty sure that makes his contract guaranteed. So now, he's locking down a roster spot that you may want to use later for a buyout player pickup or midseason trade. At 5 million, he might not be easy to just dump midseason. So there is risk there.
Now, if he gets released, clears waivers, and is willing to choose us at the vet minimum, than I am ALL for it.