That's valid from a certain perspective. Technologically, Shuttle was a tour de force, although economically extremely terrible. Once it was decided to retire Shuttle,p probably the most common perspective among industry experts was that Shuttle "proved" reuse was not economically feasible and expendable was the way to go. So while Shuttle pushed technology to the limit, in many ways it actually held back development of reusable rocket technology (at least from a national policy perspective, which might have actually been for the best as it created the space that SpaceX needed to develop their solution commercially).

So in practical terms, Shuttle might have actually held back reusable rocket use more than advanced it. Fantastic achievement, though, and really not too bad economically when you consider all of its capabilities (only a fraction of which were used for any given mission, though).

Given how much of a dog the Shuttle was, you're not really making as strong an argument as you think here.

> NASA was reusing orbital 'upper stages' (although not boosters or ETs) for a few years. This little thing called a 'Space Shuttle.'

Oh, the thing that had to be essentially refurbished before being able to fly again?