DW is an all-NBA defensive player and an All-Star level player. There is no question that were he an UFA this summer, he'd get multiple max offers.As an intellectual exercise, people need to try and make a stronger case for why DWhite would be awesome on other teams. Everyone is searching for the evidence for why he'd be less valuable, to convince themselves it's really likely the Cs can re-sign him at $31/year.
I don't know DW from Adam so I have no idea what he's thinking but my WAG is that DW isn't taking a max offer from a non-contender just to get paid. But there are several contenders who would be great fits - he would great in GSW (if they could work out a sign-and-trade), OKC (if they really wanted him, which I'm not sure they would do), NO, IND, etc. He would probably be happy playing 45+ minutes every night for Thibs too.
But fortunately he's not a UFA this summer and as BenHogan and others have mentioned, hopefully he's happy with the additional $120+M of guaranteed money plus a chance to win championships rather than playing out the final year of his contract and going through the FA process.
BTW, if he doesn't sign the extension, my guess is that he's gone, which would absolutely suck.