Then do that. I don’t see why Apple should be obligated to help with that though.
If this doesn’t work for you, simply buy something else.
Lets pretend an oracle handed me a fully functioning version of Android 5.1 (the best looking version of Android) for the iPhone $whateverIsCurrent. Installation is fully automated and works 100% of the time. All I have to do is plug-in my iphone to a Mac, paste in the signing key, and hit okay.
I am no closer then to installing an altOS then I am now. I can't install it without getting my hands on the signing key. Which means, hacking or corporate espionage. One is probably illegal in some countries and the other is definitely illegal in most country.
For the record, I don't care if I run iOS or anything else. A phone is a phone is a phone. But a few comments up, the claim was made that Apple isn't stopping owner's from doing anything and that simply isn't true. It is using software to place the weight of the law against the user.
The boat-loader is locked down, without an exploit, you can't unlock it. No legitimate reverse engineering is going to grant you access to a low level signing key.
That is a restriction on "whatever I want" and quite a few other things.