I don't quite follow the medical analogy used, since only the mechanism was in dispute and not the fact that people were getting sick. If it was directly analogous, people would have been denying that sickness happened at all, just like how there are far too many people who don't believe that climate change is happening.
However, I agree with the gist: it won't happen on a broad scale until it's more profitable to keep humanity alive than continue killing it. The current generation of c-level officers is old enough that they won't live to see the effects of their greed, but the next generations will, and you can't make money if you're constantly fighting the weather or your workforce is dying of heat stroke.
It may be too little too late by that point, since there's a lot of biological systems that are negatively affected by climate change, but I don't doubt that profit will be a big motivator.