Also, SpaceX being the first to demonstrate it was feasible. There were naysayers even after they landed their first booster in December of 2015. ("refurbishmen

Also, SpaceX being the first to demonstrate it was feasible. There were naysayers even after they landed their first booster in December of 2015. ("refurbishment will cost too much!") Now that SpaceX regularly flying a booster 5 times or more and have at least 10 boosters in the fleet, the only people arguing that reusable space hardware is not worth doing are people with a vested interest in old-space-hardware designs.