NLP will only continue to improve in the years ahead. I've got a few echo's around the house, and yes the current implementation of NLP is not perfect. It requires some modification of how the user speaks, but the first time you say "Alexa what's the weather today?" and Alexa comes back with the day's forecast is a jaw dropping moment (at least for me it was). I believe voice activated devices will ultimately be placed all over the house and we'll communicate with our computers for a lot of various tasks through voice - it's just natural for humans. Think of all the mundane tasks you do typing into a computer - setting calendar appointments in outlook for example - and then think how many mouse clicks and typing are required. It's so much easier to just tell a computer using a voice command.

The privacy issue is easily solvable IMO. Google already requires a physical mute button on their devices to disable the mics in hardware not just software. It will require either user trust (admittedly in short supply with tech companies lately) or some government regulations but there is no reason even today for devices to have to "record" your conversations in order to process. As long as you require a "wakeword" to tell the device to start listening to your next commands the device doesn't need to record all audio all the time.

Have you ever written an Alexa skill? Because as soon as you try that, you realize the limits of the slot/intent system that Amazon is pursuing. You will notice this especially when it came to names and letters. We built an Alexa skill that allowed sales executives to use an Amazon Echo to ask Salesforce questions such as "Who was my best sales person last month?" That worked great, but the executives we talked to mostly wanted specifics about particular cases. And Alexa could not figure out the company names. These tripped it up badly:

Avon

IBM

Sinopec

Volkswagon

Alexa could not get these, which made the skill nearly useless.

It is much easier to simply use a keyboard.

And please consider the failed promises we've heard over the last 3 years. Remember "Invoxia will enable Alexa to tell which person is talking":

http://www.smashcompany.com/technology/invoxia-will-allow-al...

One as limited options in terms of forcing Alexa to pause in certain parts of a word:

http://www.smashcompany.com/technology/using-a-glottal-stop-...

I wrote this when I was still optimistic:

http://www.smashcompany.com/technology/how-to-build-conversa...