I don't think it's as much age as it is experience and maturity. If the age was raised to 18, then the people will be just as new to driving as someone that is 16. Besides, at least in my state you have to go through a driver's training class that includes country and city driving in order to get your liscence at 16.
Not every teenager is irresponsible either. I'm 16 and when most people imagine a teenager's car they expect loud music, text messages, and basically a party. In my truck the party consists of, me driving with my Ipod set on a loop of my favorite songs plugged into the radio (quietly I might add), my friend with my Ipod playing games on there, and my brother passed out (sleeping) in the back seat. At least that how it was when I was shuttling us to school and back. I don't know about you, but that sounds like a pretty lame party.
As far as restrictions go, I say they are fair. For the first six months you can't have more than 2 passengers in your car, can't have hands free devices (for cell phones) at all, and you can't be out passed 1 am. to sunrise. If you have no accidents, these rules will be lifted.