If Apple allowed sideloading then you're experience would be 100% identical. You would have the freedom to continue using the App Store just like you do today and have a nice curated experience. Contracts would continue to work just like they do today. The thing is, the rest of us would have -more- freedom as we could, optionally and of our own accord, use apps outside of the App Store as well. Nobody is harmed and everyone is happy. Everyone either has the same amount of or more freedom and safety.