This one isn't even hard to argue against; Apple being a good steward for its storefront was true in 2011. It is no longer true today. I'd consider a tech-illiterate user less likely to randomly lose a lot of cash by using different storefronts from the Apple App Store (or again, the Google Play Store), if only because those different storefronts actually do a bit of curation instead of focusing on quantity over quality.
[0]: Most of the ones listed here apply that aren't "non-free dependency" or are meant to be a category filter like NSFW. I'd also throw in "microtransactions to unlock basic functionality", but F-Droid effectively bars those with other inclusion rules. https://f-droid.org/docs/Anti-Features/
The app review process on the appstore isn't designed for the user's benefit but Apple's benefit. There's no problem publishing a casino game but if your app doesn't pay the tax, be sure that it will be rejected.
Uhhh are you claiming ubuntu has a stricter app review process than apple has with the iphone app store?