I'm not sure that is correct. As far as I know, there are in fact quit a few non-Apple headsets for the iPhone.
What's revolutionary about the iPhone is how ridiculously easy it is to operate. A device can have every function imaginable, but that won't make a difference if the user does not easily understand how to exploit them.
You should try out an Apple product sometime and experience yourself that Apple is much more than marketing.
Can't use non-Apple headsets?
I'm not sure that is correct. As far as I know, there are in fact quit a few non-Apple headsets for the iPhone.
What's revolutionary about the iPhone is how ridiculously easy it is to operate. A device can have every function imaginable, but that won't make a difference if the user does not easily understand how to exploit them.
You should try out an Apple product sometime and experience yourself that Apple is much more than marketing.