Eh, maybe. I feel like once you're a sellout, the situation is out of your hands. As a founder, you have to accept that, or you shouldn't sell the business in the first place. Or you could structure some very strict buyout terms, I suppose.
Companies pay obscene amounts of money all the time for things don't end up using. Google does it all the time. Was Disney acting a fool here? Absolutely. But is it within their rights to do so? Also yes. (I'm actually kinda surprised they didn't sunset it sooner, since I don't think it was making much money.)