We did consider that, but it's a bit hard to fit all the electronics well and distribute the antennas optimally and keep that consistent across people and glasses. Best to have a predictable device we can engineer to the needs of this application!
Does it work firing up from the neck? Could you do a necklace style one?
Because this is an input device, I would love literally any form factor other than glasses. Smartglasses had a stigma back in 2012 when I was making them out of duct tape and beagleboards. Behind the head, in the same format as bone conduction headphones (even if there are sensor wings protruding forwards) would be so much better. In fact, combining this with bone conduction would make for a full silent and internal communication device.