It is funny that you think google would not be as restrictive - if they feel they can do it without losing market share.
Look at what they're doing on youtube now. It was all free and easy on the way up, now it is dominant - and suddenly they iron fist comes out.
What keeps these companies honest is several market leaders fighting each other to please us, not lemmings running to one platform.
any app that threatens the google business model will not be allowed on android, if not now, then later, after you have nowhere else to go.
The crucial difference is that if an app in not allowed in the Play Store / Android Market it can still be installed on Android because Android allows for installation of Apps from outside the Play Store / Android Market. The censorship in the Apple case arises not because of the policies of the iTunes store but rather because IOS
only allows for installation of apps from the ITunes store. The restriction in IOS of only allowing applications from the ITunes store to be installed on IOS means that in many cases Apple
is always in the wrong regardless of whether they allow or not allow an app in the iTunes store. The same situation arises with Windows 8 RT and its restriction of only allowing apps from the Microsoft store.
Edit: The one sure way to prevent this kind of censorship is an operating system that contains GPL v3 code, because if a vendor tried to restrict what apps can be installed on such an OS they would be liable to copyright infringement. This is why GNU/Linux is currently the best option for an OS.