Because just like us, if we were playing for Manchester United we'd move heaven or high water just to get to play for the club even if they were terrible. It's the same for De Jong, he's wanted to play for them since he was a child and he is doing so, so he doesn't want that to end. Add on top the beautiful location and such and why the hell would anyone want to leave that scenario? I get they have treated him like dirt this summer and honestly he has a bit of stockholm syndrome for just accepting this. If he can just get past the transfer window however then Barcelona cannot do anything and i've no doubt the relationship will end up being repaired and everyone will just move on eventually.