I just can't fathom why any $5k/year in-app subscription should be legitimate.
You think an app can't provide more than $5000 in value to a customer in a year? Under any circumstances? Any kind of app?
It should be enough to raise a flag for someone at Apple to thoroughly review the app before approving it for release. Not to mention that software worth $5,000/yr isn't often, if ever, paid for through an app store.
Isn't it in Apple's financial interest to look the other way? The scam generates money for Apple so the incentives here are misaligned.
I highly doubt that these apps are generating such a significant amount of income for Apple (when taking into account their entire income from the App Store) that they would consider looking the other way.