As someone who has been a board member, C-level, and owner is multiple companies, including most recently one that was effectively public, I can say this isnt really true.
All board members have a duty to look out for the best interest of the company. There is no implied sense of short term over long term in a public company. In fact our company largely prioritized and looked at profits much the same way before and after the process
The issue with public companies is quite the opposite, you cant get away with shady shit as easily since you are under a much closer watchful eye.