If you're not charging, you still need customers installing and using your app. Note, I said: "Or perhaps these companies are seeing more purchases/revenue..."
Revenue is revenue, whether you get it via a purchase or via eyeballs. If companies are getting less revenue from Android users vs iOS users then there's little reason for them to invest more in making their Android ports look as nice or function as well as their iOS ports.
The key here is to look at total revenue, rather than revenue/customer. The incremental costs of serving an additional customer are negligible, while development costs are (relatively) fixed. Thus the relative adoption rates of Android vs iOS customers becomes decreasingly important as the Android user base continues to grow.
Despite the apparent swing in popularity of my original statement, I stand by it. Android is looking more and more what Windows was in the early 90s. It doesn't matter how many iOS users purchase apps; if the Android market share is significantly large it will still be the more profitable platform to develop for.
I agree, total revenue is key. In fact, that's my entire thesis: the disparity between current iOS and Android apps may be explained by the possible disparity in revenue between the two platforms.
The reason I replied to your post is that I disagree with the "Android will be utilitarian/iOS will be artsy" assertion as being caused only by market share or user expectations (though I think user expectations are also a huge factor). My belief is that one major, current reason why iOS apps are of higher quality is not just because iOS users expect higher quality apps, but also because iOS users generate more total revenue for companies, providing a better ROI. If/when that shifts in favor of Android, those apps may become the higher quality versions.
As for what happens in the future, it's anyone's guess. Heck, it's entirely possible for Android to crush iOS in terms of market share but to still generate less total revenue for companies if no Android users actually install 3rd party apps. I don't expect that to happen, but it's certainly possible.
"My belief is that one major, current reason why iOS apps are of higher quality is not just because iOS users expect higher quality apps, but also because iOS users generate more total revenue for companies, providing a better ROI."
I think that's a fair point, and one I'll readily concede. My assertion is that, moving forward, we're likely to see that key metric shift in Android's favour, barring some massie swing in adoption numbers.
Revenue is revenue, whether you get it via a purchase or via eyeballs. If companies are getting less revenue from Android users vs iOS users then there's little reason for them to invest more in making their Android ports look as nice or function as well as their iOS ports.