You're absolutely right that too many corporate employers take a "check the box" approach to being good employers. They strive to do well in rankings and to develop a good reputation, rather than focusing on treating people well.
But the bigger issue is that people have ended up in a position where they are powerless. And that is because the system doesn't see them as valuable. In an economic sense, unskilled labor isn't that valuable. But in a philosophical sense, those human beings are part of a society that should be looking out for them.
The best instrument of change in this case is government action (which I suppose means that holding this opinion also makes me a little bit socialist).
The root cause of the problem, at least in the United States, is that our educational system (aided and abetted by institutional discrimination and/or neglect) has failed to give many of its citizens the skills and knowledge they need. Furthermore, the social safety net is both inconsistent and insufficient.
As a mere business book author, I have a hard time tackling such problems, though I've certainly offered my opinions.