Actually, I never mentioned USB-C.
But let's take it as an example: adding USB-C was a great idea.
Removing every other kind of port, including the fantastic Magsafe, on the other hand, was a bad idea. Many people try to justify it by saying that it had to be done so that we can "make progress". Well I'm fine with progress, but I don't want to be held hostage. And it certainly feels like it: if I buy the new Macbook, I will be able to connect exactly ZERO of my devices to it.
But — what I actually meant was things like magsafe, charging light on magsafe, function keys, Esc key, little wire organizers on the charger, keyboard key travel, or the headphone jack on the iPhone. You could easily make the same case for battery life (I'd happily trade 2mm of thickness for longer battery life) and ports: I really don't care that much about thickness, so don't sacrifice ports to make my machine 2mm thinner. Again: we lose good functionality for no good reason.