A lot of it with Price simply seems to be ego. Before working with Sony, Insomniac made a couple of decent games with great tech that nobody played. Then Spyro happened, which was so good Sony bought the publishing rights from Universal and EVERYONE noticed the games.
Price never liked that Sony got so much credit for Spyro and Ratchet games, yet without the aid Sony gave Insomniac, they made Fuse, which was technically solid, but completely uninspired. It almost bankrupted Insomniac. Sony offered a buyout MUTIPLE times, but it took the cratering of Sunset Overdrive to finally push Ted to take the Sony deal.
It isn't going too far to say that Insomniac would not exist today without Sony, and they likely would have faded away into obscurity without them, and Price wasn't happy about it for a long time before accepting the inevitable.