I have never seen a UI from the seventies, but I imagine them being more DOS-y. Yes, the design has not received any major upgrades for 5 years now, but this also makes users "feel at home". I once switched from my iPhone 1 to an HTC Desire because I wanted a fresh look - but boy did I wish my iPhone back after some weeks.

I'm now both an iOS & Android dev and designer (and owning quite some devices from both sides), but I'll choose an iPhone anytime over iOS. There is no Android experience. There is only a Galaxy Nexus experience, an S3 experience,... But there IS an iPhone experience, and I know that my phone won't restart on me when I want to show my ticket to the train conductor.