That's often the rationalization for most "perfect" and "ultimately reusable" code I see, however what I've seen too many times is code that ended up turning in

That's often the rationalization for most "perfect" and "ultimately reusable" code I see, however what I've seen too many times is code that ended up turning into shit even when the creator remained the sole maintainer. Blame often gets passed upwards to some product manager or sales coming up with some outlandish business requirement, but honestly the real reason is that the code wasn't that flexible to begin with. Which is perfectly fine, not all code can be flexible and infinitely reusable. Perhaps we should stop forcing every single file to be.