It’s not that they don’t go out of their way to support it. They actively try to stop it. All jailbreaking is, is gaining root privileges on the device. They could just add a little toggle button saying use at your own risk, we don’t support it.

By making it so hard to jailbreak and so hard to install apps not from the App Store, they make jailbreaking not the answer.

Their goal/feature/product, whatever you want to call it, is to create something secure enough that grandpa can’t get tricked into getting owned. Anything at all that allows people to disable security becomes an immediate threat for that type of user. If the side effect is that they prevent people from jailbreaking then so be it because they have no desire or obligation to support those users.

Yes, let's add a potentially system breaking switch to a consumer phone.

Believe it or not, the world doesn't revolve around the software geeks.