This will not happen as long as Apple's cut percentage is lower than the percentage of users that will give up or not download the app when asked for their credit card in-app.
Obviously any reasonable Apple's cut will satisfy this requirement.
4 users or 4 million the review process needs to be done and done well otherwise it’s just as risky as installing random crap people download from the internet. So the issue is Apples ‘cut’ needs to cover all those apps with few buyers.
It’s a complex problem because applications like BonziBuddy mean you can’t actually trust users to detect issues. That’s not to say Apple ensures quality, just that minimum standards have actual value.
On the other hand it’s reasonable for large companies to disagree with subsidizing lone developers. As such a substantial fee to submit apps would likely be required.
Obviously any reasonable Apple's cut will satisfy this requirement.