Earlier quoted context omitted.
So you're effectively saying that Apple must allow a user to install malware (likely unintentionally), but then Apple is also responsible for paying to fix it? I feel like I have to be misunderstanding you because that makes no sense.
What it seems like they're saying is that Apple should operate like a car manufacturer, wherein if you put some aftermarket shite in your engine, you can't get a warranty service, and likewise if you don't do your due diligence with what you put on your PC, Apple should be able to deny service.
While I may not always agree with Apple's approach I can understand their reasoning and don't believe that it simply comes down to earning a few extra bucks with the 30% cut in question and all the seemingly drastic measures that come with it.