> The Space Elevator has the largest potential for expanding human civilization.
The SE is a *tool*. It is not a goal.
> silly trips to the moon and back to gather pretty rocks and take pretty pictures is mostly pointless.
True. That's why nobody is seriously discussing "silly trips to the moon and back to gather pretty rocks and take pretty pictures is mostly pointless." Those who are not completely ignorant are discussing the moon as a source of vast income, specifically in the energy market, and secondarily tourism and eventual colonization.
> Then we can get to the good stuff like constructing a Dyson sphere or ring.
Not for several thousand years, probably, if then. Ringworlds are beyond any known or even conceived structural material (tensile strengths *millions* of time stronger than nanotubes needed), and of course the "Dyson Sphere" is not what Dyson described (and not is it feasible).
I'm aware of the timeframe involved with even starting a Dyson Sphere. However, it is a direction into which we may want to take a step.