Most fair-minded people would agree that people ought not be penalized for something they have no control over -- but that they shouldn't be rewarded for those things, either.
But some of the original causes have since been turned on their heads: minorities and feminists now demand discrimination in their favor.
Prejudices of all sorts are now analyzed and even invented by social justice warriors. Yet nobody ever seems to complain about prejudice against the dumb. To be honest, it's what some of these other movements have sort of morphed into anyway. So why not call it what it is?
In an era in which tests themselves are deemed "discriminatory," it's high time someone took up this cause.
Are dumb people not human too? Being dumb does not make you a bad person. Should they not have civil rights? Why should dumb people be excluded from the better colleges? Why should they not have a chance at the highest-paying jobs?
Why should this be the disability that dare not speak its name?
Just think of the great slogans that they could (mindlessly) chant:
"We're dumb, but we're not scum!" (To the lower-IQed, rhymes seems to imbue more meaning and truth to whatever they're saying.)
"'Dumb' is a four letter word!" (Or, perhaps, more in character, "'Stupid' is a four letter word!")
"America was built on the backs of dumb people!"
A dumb person could say, with that vague but unmistakable sense of hysterical victimhood/entitlement, "I am a person of stupidity."
In fact, instead of trying to win arguments by logic, they could simply fall back on, "You're an intelligencist!" in the same way in which liberals try to end arguments by calling names.
There's really no argument against that.