My thought was that this device can be useful if you are alone in the house, or are away from home. If you are alone, the gadget can be a safety feature, where you can know who is at the door before opening it. Other items do this well.
What makes this item unique, is that if you are out of the house, by answering the "intercom", it may discourage a burglar who may be ringing doorbells to discover if a house is unoccupied.
I'll admit I've not given this a tremendous amount of thought, but I'm leaning toward, what boomer said, this not being appealing to me.
hmm...yeah, other items let a person see who's at the door as well. Such as a simple peephole.
Lot's of times I don't answer my door, even without looking through the peephole. Just don't feel like answering the door. Just like I don't answer the phone if I don't feel like it.
I don't feel like I personally need to be "on" all the time, and available to every tom dick and harry who wants a piece of my time.
Don't really get the safety aspect of it either. Let's say someone really wanted to get in your home, while you were there. Lot's of people fall for the old trick of someone saying there's someone out there that needs help, etc. If they catch on that you're not actually there, they might decide to just break in and steal your stuff.
Personally, a device like this feels like one more thing for a person to be enslaved to.