I have no problem with the product category Echo Dot and Google Home sit in, and can see why they make interesting gifts, my only issue is with the surveillance aspects of these devices.
Why do I think people bought them regardless of this issue? I'd suggest either surveillance wasn't forefront in their minds, or it doesn't bother them that much.
What's interesting to me is to compare these devices to Google Glass. There was a huge backlash about Google Glass as it was obvious people were being recorded without their consent. You had people wearing the devices getting called glassholes, and the devices being banned from certain venues. Compare that to the Echo Dot. The level of unwarranted surveillance with Google Glass and Echo Dot is pretty much the same, but because one is less visible than the other it doesn't get the same level of backlash. Is there something about audio surveillance which makes it more socially acceptable than video surveillance? If a future version of Amazon Echo came with a camera that watched your actions, would that get people to see the downsides of these devices? I'm not sure.