It's both. But it's definitely an argument I've heard used against increasing automation multiple times including in historical contexts, so I'm unsure why you are saying it is not.

Indeed it is. And if you look at it, most of the arguments against tech in general - including all the hand-wringing about AI, privacy and evil tech bros - they're all arguments against capitalism. But it would be boring to repeat the same thing that's been repeated for the past 100+ years, so people instead confuse symptoms with cause.

If capitalism is defined as "everything people do that has has negative externalities" that's tautological and useless.

It's not that. All these things have a common root cause in the form of businesses accumulating capital and making decisions to abuse people. The public discourse is distracted by focusing on minutia - AI does this, robots do that - instead of noticing the common thread: business people decide to use this technology to hurt people.

We don't always get to pick independently. Capitalism is largely a force of nature. Even Communist societies end up becoming state-owned capitalist.