But its usually just the door that is hard to get into, once through the door its usually smooth sailing. Actually, this occurs in many exclusive programs/institutions over and over again. But in reality, they have to be selective: the world doesn't need that many engineers, especially ones that aren't that smart, just like we really don't need that many doctors (especially ones that aren't that smart). Computer science is the same: sure you could double or triple the size of your program to except just anyone that wants to program, but then you would flood the market with substandard talent and your reputation goes into the trashbin!

Now, would we prefer a hard program where students would fail out instead of being stopped at the door? This also seems like a waste of resources, but it could work given the right technology (e.g. online courses).