I would argue that elegance and being easy to program are virtues by themselves, because it makes code easy to understand and easy to maintain.

A one-to-one string to filename mapping is straightforward and elegant. It’s easy to understand (“a filename is a unique string of characters”), it makes file name comparisons easy (a bit level compare suffices) and as long as you consistently use the case that you intend, it doesn’t behave unexpectedly. It really is the way of the least surprise.

After all, case often does have meaning, so why shouldn’t it be treated as a meaningful part of a filename? For example: “French fries.jpg” could contain a picture of fries specifically made in France, whereas “french fries.jpg” could contain a picture of fries made anywhere. Or “November rain.mp3” could be the sound of rain falling in the month of November, whereas “November Rain.mp3” is a Guns N’ Roses song. All silly examples of course, but they’re merely to demonstrate that capitalization does have meaning, and so we should be able to express that canonically in filenames as well.