People avoid voice conversation because they don't want to deal with human live interaction. Most people don't mind talking to themselves, as sad as it sounds. I'm guilty as well.

As someone who needs glasses to use computer, it's really convenient to be able to use voice for interaction, also while driving or at home in the kitchen. I'm waiting for good smart glasses as well, since I don't want to have to keep taking my glasses out just to check any piece of information -- menu, price tag, train time, and so on.