@manored,
(1) All people are stupid.
This is a universal statement. In predicate logic, it looks like this:
(2) ∀x(Px→Sx)
And the English phrasing of (2) is:
(3) For all x, if x is a person, then x is stupid.
This statement, if true, records a "fact" about the world. How might you go about determining that truth value?
To talk about "society as a whole," supposing that society as such is constituted by all people, you suggest that you hold (1). Because if a person falls into society, and if you think its "just society as a whole," then you must hold that all persons found in society are stupid.
But what about society makes them stupid? Suppose
(4) Society is X, Y and Z.
Whatever the values of X, Y and Z, would that guarantee that all or most or many or even few people in society are stupid? What about one person in particular? If you affirm this or deny this last question, either way you could then move on to "broaden your scope" and start validly arguing that "few," "many," "most," etc etc etc are stupid.
So I must ask: Does your set of "most people" include those who do not constitute society? How would you get around faulting "society" without ultimately (and unfortunately) saying "all those people in society"? Are people outside of society "stupid" or X, Y or Z?
(5) Most people in society are stupid.
This is an empirical claim, as most take it. Its truth conditions are contingent on some facts about the world; more specifically, facts about "society." This reason comes not from "people" or "society" or what it means to be stupid, but for the fact that the use of "most" presupposes some standard of comparison. That standard imposes a sets of individuals (presumably members of "society") whereby you must show that the "fewer" set is constituted by "smart" people or "intellectuals."
So your question is fundamentally empirical. Generalizations are empirical. Supposing it is "correct" to affirm (5), what would make it correct? Well, perhaps IQ tests and standardized surveys. But which questions do you ask? How do you know if you have "smart" questions which will accurately and reliably tell you who is smart and who is stupid?
And correct for whom or to whom? When you say "correct," what do you mean by it?
Suppose that I got a perfectly accurate report that showed "most people are stupid," and God told me: It is perfectly accurate report. What a strange supposition!
"Stupid" seems like such a crude and unhelpful term. What are the necessary and sufficient conditions for "stupidity"? What does one have to do or be like to be stupid?
And what about 10 people? Is the criteria for one like the criteria for many?
Is "herd mentality" "stupidity"? Is someone stupid for simply following the leader? Do you not follow the leader sometimes?