If people are not influenced by advertising and marketing why then do governments put fourth propaganda, why is advertising a multi billion dollar industry, why is it an extremely sought after undergraduate degree, why are there advertisements literally everywhere you look? The answer is because it works, and it makes people a lot of money and gives them a lot of power.
We are highly influenced by the mainstream and by culture, I mean culture is what is allowing us to communicate with each other by providing us with a set of symbols (alphabet and English language). In fact we don’t know what we don’t know and therefore can never truly be objective in our view of the world, it’s always built and based off of cultural artifacts and norms.
So it’s not a problem per say that people do the wrong thing at large, it’s simply a fact of life, people tend go with the flow. That means people who don’t go with the flow need to make the flow flow better. Or else you are suggesting we leave normal people behind because they suck. Where I personally think we are as individuals defined by how we help people that are weaker than ourselves.