There are several reasons for the platform dependence, iOS and OS X, are the same at their core. You can also share code bases to a large extent.
I understand the barrier to entry might be price, so maybe get a Mac mini? They're very capable machines. I know plenty of iOS developers who use windows or Linux normally, and keep a mac mini just for iOS development.
In fact, I saw a lot of Java developers using Mac too. I was thinking like you before, until I finally save up enough for a Mac, then I never look back, it has become my main development companion, as well as for my part-time studies, my company are MS partners, but in the end they also bought a Mac for the development needs, to develop an app for iPhone to work with our ASP.NET web system.
But then you can use Adobe Flash and AIR to develop for iPhone, and you can still use your Windows, so not necessary a change.