Even on the old Commodore Amiga computers, it was regarded bad practise to make timing loops like that.
The Amiga had different CPU speeds across models, though. Busy loops are reliable only when you know the CPU speed perfectly (and you know other hardware won't mess up with it, like e.g. power management features).
Yes, that is very true, still people (ab)used busy loops on that platform, at least in the early days before the faster models came around and wrecked havoc on old programs.