If I am a factory, I can't build iPhones and sell them to people. Even if I was previously a factory that Apple contracted to make iPhones previously, and therefore they are exactly the same.
On the other hand, the same arguement does not apply to refrigerators. Most refrigerators are basically the same. It is easy to provide alternatives that are almost the same.
This is not the case for smartphones. Smart phones are a strongly differentiated good, and another company can't just make an iPhone that's exactly the same as Apple's iPhones, as that's illegal.
Therefore apple can do whatever they want with their iPhone, and nobody can really make the decision to buy an iPhone that doesn't have these restrictions.
Indeed, when people tried to remove these restrictions, Apple tried to sue people who jail broke their phones. That's not ok. It is horrible of them to have done that.
Nobody can make the decision to buy a Chromecast or an Echo or a Nest or a Tesla without restrictions inherent to those devices. In what way is Apple special here?
Apple is different in this respect in that if you try to do something with the phone that you bought, whether it be repairing it against their wishes, jailbreaking it, or whatever, they'll sue you.
These matters have come up multiple times in the courts, and this is what Apple does.
The only reason why they aren't sueing customers today for jailbreaking is because they lost that court battle. But the intention is there.
I don't want them to have the ability to sue anyone ever for doing something to property that the customer already owns, because that's how property rights should work.
Other companies generally do not sue you for modifying hardware that you bought.
For the record, Apple has never sued anyone for jailbreaking. They did argue it should be illegal under copyright grounds, and lost that argument. If that's a dealbreaker for you, so be it.
Apple does not rent you a device. They sell them. Once they sell them, they should be yours. That's how property works.
If a refrigerator company put in special protections that made it difficult to put food in your refrigerator, without paying a 30% tax, would you accept that? I wouldn't.