IMO, outside of the tech world, nobody really cares about USB-C - or at least - not enough to drive upgrades. It's just what one end of the power cord looks like.
I'm not trying to say that will drive massive upgrades in and of itself, but I can definitely see it being a nice-to-have at the margins and help a nontrivial set of people pull the trigger.
I don't understand the need to have a single connector vs a block with interchangeable cords, but I also don't care that much about it so I might be missing something.
I mean my MBP has a MagSafe charging port, but I use USB-C for powering that too. One type of cable for everything.
“Why do I have to buy new cables? What about the stuff that uses the old cable still? I need two now?”
I agree it’s the other new feature, whatever they are, that would be primary drivers for most people.