In CS courses you teach students to be CS scholars so it's normal that you teach the fundamentals to make them achieve that goal. When teaching stuff to a people of different background you need to first ask why, why do you need this and then adapt the curriculum to that.
Weeder courses signal to the students "Hey, if you're struggling in this class, it's not too late to switch majors". Every student "weeded out" frees up a disproportionate amount of resources for the rest of the students who are ready and willing to learn.
But sometimes they are a real problem from the student’s perspective, especially when the class is made artificially difficult to pass, and this does happen. They are not always used to prune students who can’t handle a degree, they are sometimes used to limit enrollment in a program that doesn’t have enough capacity, which isn’t an issue with student preparation or capabilities.
Their proposals were beaten back, but it took a lot of effort.
Czechia, 1998-1999. No tuition involved, study was still completely financed by the taxpayer.
The absolute lack of context and meaning to anything that was done in math education meant I never appreciated them, they were literally just wastes of time to me. Anything beyond simple arithmetic made no sense to me, because I was never taught how they made sense.
It was only once I started playing around with programming when everything suddenly clicked. All at once, concepts like variables and equations had meaning, I could sincerely understand what the numbers and letters stood for.
Math education in general really would benefit students of all ages more if they had more of the Hows and Whys before engaging in all the Whats.
Out of necessity, academia historically selected for students who could learn from being read to just once without much context, and there was little pressure to fundamentally change the education format. It's very easy to better serve most modern students by actually designing the program for those students for a change.
Debates over this get muddled by zero-sum concerns. E.g. catering to the average student hurts the top performers; putting applications first replaces rigorous education with training.