Quote Originally Posted by Jaxilon View Post
It may be funny when you think about it but then honestly, most people who have lived underground didn't bother carving out square rooms (or did they?). Why would they, it's too much hassle for no real benefit? Kind of makes you start wondering why we build in squares at all. They stack nice I guess and are pretty structurally sound.
Actually the vast majority of egyptian tombs are made up of squares and rectangles.

As for why, More usable space.