I feels as though the world has soured on the GPL in recent years, but whenever I see this type of sentiment—that open sourcing work is just a gift from small developers to big tech companies, or something thereabouts—I think, wouldn't the GPL solve that problem?
Sure, big companies can still use GPL'd code, but they're forced to give back as much as they take, which is exactly the outcome you want.
(This doesn't necessarily apply to the situation with AppGet, however.)
It seems toothless to me. A relic from a byegone era when companies cared about ethical behavior.