Let's not fall into hyperbole: there's a few places that have banned Glass, out of well, the entire world. That's a long way from "most of the time" or "many places."

There's a lot more (and by that, I mean orders of magnitude more) places that ask you to not use cell phones than places that ban Glass (restaurants, movie theatres, coffee shop lines, airplanes, customs, etc). But nobody would claim that makes cell phones useless.