Well, if KD goes to SAS, they will contend, but for how much longer? He'll be middling forever in OKC if he stays. If he comes to Boston, he contends AND the team grows and gets better every year. Especially if Smart reaches his full potential and Isaiah is still killin it. That'd be scary.
Boston has no one on the level of Westbrook. Or Ibaka. Or Adams, for that matter.
So why does Durant leave the "middling forever" Thunder to join a "contending" Boston team?
No one close to Westbrook but he is a free agent next year and has demonstrated (at least to me) that he cannot be a consistent quality facilitator at the end of important playoff games. I guess we'll see how the rest of the playoff goes but so far OKC made the one Finals where they got shellacked and are clearly number three in the West. In other words they were clearly passed by GS and the rumors of the Spurs demise were greatly exaggerated.
IT may not be Westbrook but he is an awfully good player and is clearly better than Adams and probably better than Ibaka (yes, different positions). All those bigs don't help OKC versus the Warriors much. Waiters sucks. Celtics are younger and better at defending the wings.
Boston is already close to as good in the East as OKC is in the West. The path to the Finals is easier in the East. Adding Durant and another max along with a trade or impactful rookie plus the BK picks plus an excellent coach in CBS going forward means something.
Durant would be the clear #1 option and Stevens would be drawing up better end of game and out of bounds plays than OKC has. This year has lead me to think the problem may be hero ball and lack of clear delineation among the 2 stars in OKC rather than the coaching. If Durant stays, as he is likely to do on a 1 year, we'll see if they are better in year 2 of Donovan.