CS degree is not all that fun. You’re better off doing math and just learning to code on the side.
... because they know less about programming, and thus think much less deeply how a novel abstraction could look like which solves the problem much more elegantly.
In other words: these applicants more obediently do their work instead of regularly questioning whether there could be a better way and thus rocking the boat too much. :-(
I do work with people who have a math major. Let me put it this way: if they were interested in finding and applying novel abstractions for programming, they would for sure often be very capable in this, but people who majored in math often rather love to apply these skills to more mathematical problems in their area of interest.