You answered yourself in an exemplary fashion, but I'll state it explicitly (and simply). People don't think about it. I'd like to imagine anyone who realises the implications of owning such a device would refuse to own one, although I know I'm mistaken.
I don't mean that people should know better (although ofc they should), but new technology is all too easily likened to any household appliance nowadays. Alexa is a utility, for better and worse.
It's my opinion that we should very much attempt to educate the non-professional about the realities of these spy-machines, in much the same way we don't teach people about dishwashers.
As for the article: I find it morbidly curious that I could tell Alexa who is murdering me. A benign 1984 for now I suppose.