I would have preferred an actual reboot. BUT NO they just had to shoehorn the original universe in there somewhere and stick Nimoy in both films.
That's the brilliance of this reboot, in my opinion. It resets pretty much everything without ignoring that things used to be different and that it existed. Not bad for a single movie.
Its causes a ton of continuity errors, especially if they do not adhere to the prime universes History before the kelvin was destroyed. (ie: Khans accent)
Old Trek was never particularily strong on continuity anyway, so I've let that go somewhat.
You're basically saying that new actors can't possibly play older characters, which is not very pragmatic.