> Or, in other words, the perfect amount...
Well no, because the job doesn't end when it's "done". Minecraft is the perfect example:
In the earliest versions of the game, blocks were all basically homogenous cubes of some material, so they didn't need to be oriented. Later, blocks were added that did need to be rotated in various ways, e.g. torches, stairs. But each of these blocks had their own private system for choosing, storing, and rendering their orientation. These systems were often similar, but not identical. At this point, roughly half the blocks in the game are orientable in some way and there is still no generic orientation system. Such a system would have avoided massive amounts of redundant code, prevented many bugs, made the user experience more consistent, and made various 3rd party tools much easier to develop.
"You ain't gonna need it" is a cop-out. You are going to need some things. The trick is anticipating which things, and it will definitely pay off if you can guess correctly.