How is the deaf peoples' lawsuit going against smartphones for the same reasons?
(Coincidentally, bone conduction is already used in some devices for people with impaired hearing.)
First, bone conduction doesn't work with all deaf people due to varying degrees of hearing loss. And it's already very controversial to begin with due to different viewpoints between the audist and Deaf worlds. I, for one, wear a hearing aid and have no desire to have bone conduction.
What you speak of is considered a cochlear implant. It doesn't sound exactly the same as those who have hearing aids which is somewhat complicated to explain.
Second, when deaf people see the Apple Watch, the only thing going for it is the notification factor alerting them of certain things. That's about it. But when it comes to communicating, it doesn't work. Most of them use sign language and using that with a watch is counter productive.
Especially with crack pot dreams of using video chat on a watch a la Dick Tracy which would require high speed bandwidth to pull it off and take up a lot of battery juice. The only limitation would be small video clips to be sent back and forth in short burst messaging similar to what you see on the iMessage features.
The use of video chatting is more commonly used on smart phones, tablets, or desktops. Or even video phones that replaced the TTY ( the latter is now web-based ). They use sign language on screen back and forth the way FaceTime was intended ( or even Skype ).
Texting is still the most prominent method of communicating. I do it all the time and would not even think of doing that on a watch. I have a data only plan and it blocks every voice call that comes in.
Some deaf people cannot hear their own voices and some do, depending on the degree of hearing loss. The point is, if they can't hear their own voice, it's pointless to talk on the watch.
And when they see that every hearing person can use that feature on the watch, they going to be thinking " Something's not right here. Why can't we communicate via the watch and they can? ". Same thing with using Siri while driving. Most of them can't use it and besides, some states ban texting while driving and that makes it worse for them.
Maybe you might not realize it but every time Apple or any other company releases new technology, it's like opening a Pandora's Box without thinking ahead.
And your idea of bone conduction doesn't work for everybody because that requires buying an ear piece and it would be expensive. I'm aware of bone conduction headphones such as AfterShokz seen here:
http://www.aftershokz.com
I still think it's stupid to talk to the watch in public if you want to send a message to someone. But wait, it has to be paired to the iPhone for it to work therefore, it's piggybacking phone for this reason.
For other verbal commands to the watch using Siri in terms of home appliance control, carplay, music, apps and such, that may make sense if away from the phone or computer.
Personally, I would NOT want FaceTime on the watch. Seriously. It makes the iPhone pointless. And that's where having a larger screen on the phone for such video conversations or texting makes a lot of sense.