The cost is what is prohibitive for many developers, which is why web apps are easier. I don't have to buy a Mac to make them, and any body can use them no matter what platform. I used to write Mac applications back in the day, but all my friends and relatives who didn't use Mac OS couldn't use them, I switched to web apps and yes I lost a lot of features, but I am reaching a wider audience. Have any IOS developers tried to port their app to Android? just for the challenge.