Because of time bombs like "It works well enough because nobody really lives at the poles--" That's exactly the sort of thing that works well until one day it

Because of time bombs like "It works well enough because nobody really lives at the poles--" That's exactly the sort of thing that works well until one day it just breaks your code because you forgot to make sure never to to do a computation on a thing that includes on of the poles. And it won't happen because someone starts living there rather it will happen because of a complicated logical chain of reasons that make perfect sense, but only in hindsight.