Personally, I think behavior does (and likely has to) evolve with size. Unfortunately bigger tends to be worse.
Culture is also primarily a top-down flow. I'd the CEO is a screamer expect screamers all the way down and so on.
Of course there are companies, too many of them, that behave badly. There are too many people who treat other people as nameless, expendable and exploitable. There are also many others, the ones that don't make the juicy comments on reddit, which behave well, treat people as people, and so on.
Treating your work-place as a hostile environment can be emotionally and mentally draining. It can be counter-productive if the environment desires to support you.
Equally, if your environment is hostile then at least be looking elsewhere. Not all companies are created the same so there are likely better options elsewhere (although getting those posts is harder because people tend not to leave.)
Your advice rings true for many companies. But people stay in those places because they believe everywhere is the same. So a more nuanced advice might be to understand the culture and behavior where you work and decide if that's a culture you want to assimilate, and support, long term or not.
For the record, the place where I work has never expected anyone to do emails etc out-of-hours and you'd be laughed at if you suggested people should behave otherwise.