Calculus is not a hard math class and the idea that it "weeds out" students is pretty brain dead.
Meanwhile, discrete math is absolutely something you see in computer science. But, in my high school discrete was the course for people who didn’t like math, as an alternative to precalculus.
It would be much better if schools offered an AP Discrete math, and colleges were more lenient to students who are good the discrete math but for struggle with calculus.