Apple's major versions come out once a year, while Android's about twice per year. In this case Android 2.1 (early 2010) is even newer than iOS 3.0. Are you saying nobody has an iOS 3.0 iPhone anymore?
I don't think phasing out versions is a big deal for Android. It happens about as fast as for iOS (~3 years). What is a bigger deal is how fast the latest OS/API gets adopted. iOS can push out the new version in days to at least 50%-75% of the users, while for Android it takes about a year to be on 75% of the devices (that's how long it took for Gingerbread).
And the issue with that is that users don't get to take advantage too much of the most cutting edge software, until months after release, when (or if) they get their upgrade, while on iOS they can do that just days later.
I don't think phasing out versions is a big deal for Android. It happens about as fast as for iOS (~3 years). What is a bigger deal is how fast the latest OS/API gets adopted. iOS can push out the new version in days to at least 50%-75% of the users, while for Android it takes about a year to be on 75% of the devices (that's how long it took for Gingerbread).
And the issue with that is that users don't get to take advantage too much of the most cutting edge software, until months after release, when (or if) they get their upgrade, while on iOS they can do that just days later.