Part of college is growing as a human, and part of that is social interaction.

For the same reason a lot of universities in Europe require you to take philosophy. It's completely unrelated to C++ or data-structures, but it adds to your acumen as a whole.

Not that different from some universities that require you to be able to swim[0].

[0]: https://perec.columbia.edu/swim-test-requirement

I only know the Uni system of a few European countries, but generally I would expect Philosophy to be a prerequirement that you take for your entrance examinations, not during studies per se (unless you're studying humanities, of course).