Earlier quoted context omitted.
Making rockets re-usable is a massive step forward and not about 'not regressing'.
In the past we even had space ships, which could start from ground, go to space, do stuff, come back and the could be reused. Having just a rocket isn't that much of an improvement. That said: All the constraints on making it reusable and safe for humans are also a key factor why Space Shuttle was so expensive. With SpaceX's rockets not all parts need to resist the stress of reentry etc.
The 're-used' aspect of the Shuttle involved massive re-fits which took months for each vehicle. It was like having to send your car back to the manufacturer for a total rebuild (often including engine change) every time you went for a drive. SpaceX is a massive improvement in this respect.