Bluetooth headsets made you look like you were talking to yourself, breaking essentially all social norms. There's a reason they (and those who used them regard

Bluetooth headsets made you look like you were talking to yourself, breaking essentially all social norms. There's a reason they (and those who used them regardless) were widely mocked. Google Glass was obscenely expensive, invitation-only -- circumstances around its availability made it clear it's a tech demo for technology 'futurists', and not a product within reach (or intended for) the general public. Naive defaults about it recording everything caused a privacy storm; behavior on part of its users led to widespread derision. Smartwatches in their current form are solutions looking for a problem. It's obscene that notifications and fitness are the only two use-cases most makers were able to identify. All these devices are plagued by voice control: speaking to your device in public is neither very considerate to those around you, nor privacy-preserving. The fact is, even if speech recognition systems are working well, most people are uneasy issuing content-rich commands, like entire bodies of emails, in public earshot. Until someone solves this shortcoming reliably, none of these devices will see widespread public appeal.