I'm not going to address this point-by-point, because very little of it has to do with ease-of-use for either the consumer or the developer.

I'll give you this - writing for iPhone is certainly easier in the sense that you only have to write for one (maybe two) software versions. However, take a look at Tweetdeck's later response to the comments : that they had a team of TWO to deal with versioning. Sure, it's a bit of a hassle, but there are always trade-offs.

That's also not the only consideration. There are many factors - App pricing, prior programming experience, target market, etc. that play into making an application. Not only that, having one market and one system is not necessarily better, and it's definitely not a fact.

It comes back to the issue of competition; I'm not talking about Android vs. iPhone; I mean the competition between developers in putting out applications that are meaningful and easy to use. Neither system (right now) is inherently better, and I think that casting it in the light of integration vs. fragmentation turns the spotlight in the wrong direction.