I think they have decent potential and can serve a good purpose. it's just how they are being used now that isn't so great. Right now wearables are more or less just another screen for your phone but don't do as goo a job due to a lack of screen real estate.
The glasses would be great for augmented reality stuff. You won't have that good of a use for them most of the time, but they'd be good for stuff like being in the car; I could see them used to give you a HUD for your car to show speed limit and such without looking at the gauges, and they could put the cameras and sensors on the car into your field of view; escpecially at nighttime it would be great to have the lines and any poorly illuminated objects of interest highlighted, and navigation arrows would also be useful. Also for specialized fields, they could give useful data like showing surgeons real time imaging (MRI CAT scan, etc).
I find watches a bit more dubious. Fitness trackers aren't as great as companies try to make them sound. The pedometer is decent enough, though the arm-swing may induce some error, but the monitoring sucks since they can't get a good reading on things like temperature or pulse if they aren't tightened down, and even then, it's not great (more accurate reading on pulse from the fingers, and the temperature of your skin is a poor indicator of your core temperature). The other thing they do is show stuff like phone notifications, texts and who is calling, which is great, but for actually dealing with messages and calls it's likely to be better to just take your phone out.
My main issue with thm, though is how ugly they are. I want a smartwatch that I can actually wear as a fashion accessory rather than some clunckly, ugly calculator watch looking boxy thing (smart watch should emphasize the watch rather than the smart), and smartglasses would be better if they were actually glasses, though screen tech needs to come a lot further for that to happen.