What exactly is private about Google? That trading and ownership by the public creates an overarching obligation for public governance (eg accounting, written justifications, the board, etc). Google has a larger bureaucracy than the typical municipal government, likely surpassing even some state governments. Its employees aren't a tight knit private club where everyone knows everyone, but well over Dunbar's number. Google has been granted a liability shield by the public, presumably because doing so serves the public interest. Market wise, Google provides its products and services to the public. And for surveillance companies like Google, one can't even say that the majority of what we'd traditionally consider customers (but now: data subjects) have private relationships based on voluntary association!

It seems this word "private" gets bandied about as an ideological assertion - insisting that we should treat this company as if it were private, completely rejecting the fact that its current form has vanishingly few private qualities.

Private is used in opposition to public, as in 'private sector' and 'public sector', where public sector is ran and funded by the government, which means public finances, which mainly means taxes - people cant pick and choose which taxes they pay and what the money is put towards. In private sector on the other hand, people can privately decide what to invest their money in.

Sure, when you put subsidies and tax breaks into the mix the line gets a bit more blurry, but legally speaking its a well defined concept, even if not all private companies match the intuitive meaning of the phrase. And yeah, Google is a very specific case, which is why there is always some level of debate about whether it (and other similar companies) should be forced to split up, and some of the resulting parts turned into a public utility service.

I'd argue that's ultimately still a political usage, to create a motte-and-bailey arrangement whereby large corporations with more bureaucracy and less accountability than most governments are given a pass based on the merits of small nimble actually-private companies.

Google was for sure a creation of that private sector and its virtues. And even though it had some public handouts (like university research funding and the corporate liability shield), it had many private aspects - actively involved owners, a small number of employees, who were in touch with the mission, having to compete for customers, etc. But applying that term to the modern day Google as if there is a strict dichotomy of public-private seems like whitewashing the actual reality of large corporations having much more in common with government than with small businesses.