Lot of doctors in here re: Kyrie.
If after working out a plan and being examined non stop by the team doctors and then by James Andrews they've determined that running and even playing can't do him additional or gradual harm than there is no sense in him not staying sharp and being integrated into what the team is doing.
If your attitude is simply, "we have the series wrapped up, he should sit", then why not suggest the same for Shumpert, Delly, Tristan, or just about any other player who is valuable for us moving forward?
The Cavs know what situation they're in. They're not desperate to have Kyrie come back to help turnaround a series they're struggling with. So no one is rushing this for the wrong reasons. He's either healthy or he's not. If he feels good on the floor and the doctors back it up, then there is no reason not to play him smart minutes, and in doing so, create the ability to manage minutes better the next few games for Delly, Shump, and LeBron as well.
Golden State is not the Hawks. It would not be ideal to be integrating a player who hadn't played a minute in two weeks back into heavy minutes against them in game 1, unless is is absolutely necessary.