Indeed, what goes up must come down, and till recently all rockets had rather huge parts (first/second stages, boosters) which just dropped back down, usually over some stretch of ocean.
It only becomes a problem when it either drops on people on the ground (which is unlikely given the biggest part of Earth is covered with seas), or if it lingers up there and does a bull in a china shop impression among all those fragile satellites minding their own business.
Biting the hand that feeds IT
