It's worth noting that Google devices typically do not need to be rooted. For example, Chromebooks have a switch you flip if you want root. (And, Google even advertises AdBlock in the Chrome Web Store. So it's not certain that you will be forced to see ads in Glass.)

It's the cell-phone carriers (or OEMs) that want to sell you non-rooted devices, and that's a battle even Apple hasn't won.