"I wouldn't have learned this anyway!"

I work in genomics and bioinformatics now. As an undergrad I was a math major and took plenty of writing and philosophy classes on the side. I haven't taken a (non-MOOC) biology or computer science class since high school. An obvious question to ask myself is whether I regret not having devoted more of my undergraduate career to stuff I'm working on now. It would be nice to have had more of a head start in the various subjects that intersect in bioinformatics--but I was an undergrad from 2001 to 2005. Back then, next-generation sequencing did not exist (or barely existed, depending on one's definition). So much of modern bioinformatics is an attempt to solve the questions set by this technology, and that fact puts a hard limit on how much I could possibly have learned about my work back then.

As for the computer stuff: yes, some extra work in algorithms and extra practice debugging would have helped. But, as I've written elsewhere, computer science and programming is probably the best subject for self-study today (I wrote a little bit about my experience here). And--crucially--some of the most important computer skills are not things you learn as a CS major. Working in a shared repository; reading and debugging others' code; finding the right libraries to use in your own project and making sure the license permits you to do so... there are, as far as I know, not so many places in which a CS student spends a lot of time doing these things, and very few in which these are requirements of a CS major. A good friend of mine was a diligent, smart CS major who still uses his computer skills hourly in his work. He does not have a GitHub account.

So, looking back, those poetry and math and philosophy courses look pretty good. This is not only because they constituted a liberal arts education that is good to have regardless of its precise relationship to one's career, but because they--at least arguably--have been at least as relevant to my computational biology career than either computer science or biology classes would have been.