One of the most aggravating things to me in this world has to be the absolutely rampant anti-intellectualism that dominates so many conversations and debates, and its influence just seems to be expanding. Do you think there will ever actually be a time when this ends? I'd hope so once people become more educated and cultural changes eventually happen, but as of now it honestly infuriates me like few things ever have.
It is tricky to get someone to recognise that they aren't knowlegable enough. Even if you say it as gently as possible, some will still hear "you're dumb" and no one likes that.
Also it's a great tool to manipulate people : "I don't need a scientist trying to explain me life from the depths of their lab !! I have commonsense !!"
I think the best way to be diplomatic about a matter like that is to emphasize that people have different fields of experience and expertise, and you just want to share information on one of the topics where you are more familiar.
Of course, if you treat them as know-nothings who should be grateful that a Knower has condescended to instructing them and they respond as though you are insulting them, it is because you are.
My favorite quip about common sense is "common sense isn't"