Makes sense. There's no way Sony will want to give up the rights to Spidey. Even if it stops being the cash cow it is now, it behooves them to keep their mitts on one of the most internationally recognized superhero properties. And they're pretty close to burning through all of Spidey's popular villains. I think the smart thing to do would be to let Marc Webb's films run their course and hopefully use Andrew Garfield to bridge a path to a Miles Morales series of films. Peter Parker as the kid's high school teacher could be a clever way to pass the torch.
I could see a Sinister Six movie being pretty great, actually. Executed right, it could be a clever heist film that really plays to superhero tropes in a way none of the other studios have captured.
Still, they drew the short end of the stick when it comes to expanding out a superhero universe. Spidey's great, but his supporting cast doesn't have the breadth that the larger Marvel universe or X-properties do. It's a shame they don't have the rights to Fantastic Four. Spidey and FF would pair off pretty damn well for a shared super science universe, much better than FF and X-Men do.
I'll just keep my fingers crossed for a Daily Bugle spin-off.