If there’s an option to opt out of the walled garden, people will be fooled into taking it. There is no way to differentiate between you, who wants to install what they wish, and those people that believe it is really Apple cold calling them.
Apple is not a monopoly, so I feel their attitude here is fair.
That's fine too, don't strong arm me out of 30% while letting others get away with no paying that. Some people want a walled garden (you) and dont mind paying for it, others would like to install software of their choosing without letting Apple know what they install and by who.