Actors are famous for being able to recite another persons words and make it sound believable to a third person.
They do not write the words themselves, and are not permitted to ad lib the script. They have no established credibility other than to fake sincerity when they say other peoples words. If they went to school for acting, they received no education in: math, science, Civics, history, physiology, law, finance, and a myriad of other fields.
They learned to fake sincerity. That's all. If you are looking for moral or legal guidance, these are not the people you are looking for.
With all due respect, you are painting with a brush that is too broad. Men like Charleston Heston, or Clint Eastwood, or myself don't deserve to be described that way.
Great attitude. Great effort. No excuses!