.col-sm-* apply to medium screens instead of small. Intentional?

Created by: fabiogiolito

Hey Bootstrapers. Congrats on the release. BS3 is awesome.

I asked this on the BS3 pull request but didn't get a reply, but it's the one thing that is bothering me when using BS3:

Shouldn't .col-sm-* be named .col-md-* instead?

.col-12 — mobile first, so you can say it affects small screens .col-sm-12 — medium screens only .col-lg-12 — large screens only

Thanks in advance for clarifying this!

Since I'm bothering you already, I had another 3-part question:

Why doesn't col-push/pul/offset work for any screen size? Why not favor one instead of keeping both push and offset? Would it make sense to be able to target a screen size like .col-lg-push-2?