I’m not sure how privately holding the opinion “anyone who can choose non-abusive employers should choose them over abusive ones” is itself “functionally abusive”.
It’s abusive when it’s used as it was here to imply that it’s the worker’s fault for accepting bad working conditions, as if there aren’t many well documented reasons why that’s hard for most people.
Then what was the point of replying to a comment about bad working conditions to say people should switch jobs? The entire discussion was about how it’s getting harder to avoid certain practices. Do you really think most people with bad working environments haven’t considered the option?
Freedom of association is a powerful tool.