Developers would be interested in taking 30% and not interested in even trying Apple appstore, which btw sets product quality level guidelines. As a result, user experience will suffer. Those who prefer apple as it is will seek apple-level quality but wouldn't find one, because apple format is now equal to a regular one, and there is no superapple. Apple instead implicitly suggests to just charge apple users more in IAPs and for apps, when a charge is related to some electronic type of value. Whatever price developers see fit, there is no practical limit.

What you are basically trying to do is visiting a vip club (user-value wise) and then making it open to every crap dj out there, because otherwise it's "unfair". Why don't you just go to a regular one then? It is the same as this vip would turn into in a heartbeat. And where should other members who liked it go after that?