You don't know how good something is until you experience it first hand. Also I'm willing to bet that most people don't really care as much about app quality as I do, but on the flipside maybe more people would care if they knew what they were missing.
I think you are overstating the case for iOS.
I used iOS for years, and this year I switched to Android. Of my most used apps in iOS, most were also on Android and the Android versions were exactly like the iOS versions or close enough. The big-time apps like Popcap games, office doc programs, my ESPN app collection, and Samurai II act just like they did on my iPhone. Most high-dollar company developed cross-platform apps are the same on both, or very close to the same. The difference comes with the independent developer apps.
Now with those apps I have seen where the Android version was less "polished," if you count polished as that extra coat of gloss on everything. I won't deny that the iPolish that Apple's dev kit lets you add for free does make iOS apps seem nicer sometimes. But most of the functionality is there, and honestly I personally got burned out on iGloss after years of it.
The main place that is lacking on Android is video. My Sunday Direct Ticket app uses a lower quality stream on Android, and I haven't found a Air Video replacement. But on the flipside now I have access to tons of apps I use daily without jailbreaking (like a file manager), and honestly a lot of the iOS jailbroken apps have Android-levels of polish.
To me, OpenOffice is the perfect example. Sure the interface looks worse than real MS Office, but there is so much more functionality within that crappier interface. With OpenOffice I can open corrupt documents, save as PDFs, and do all the basic taks I need. In fact, for most of my family OpenOffice does everything they need. Are they missing out on the polish? No, not when I tell them it will cost them over $100 for the same functionality (or less) they get for free with Open Office.
For each person there is a different value proposition, and for most economical is what wins. Wal-Mart over Target. McDonalds over real restaurants. It happens again and again, because for most people "good enough" is fine if the price tag is free or cheap.