Rocket fuel isn't the only thing we can launch from the Lunar surface. Lunar materials such as aluminum, titanium, iron, and alloying elements can be used for simple components of orbiting powerplant structures.

As far as a hidden agenda, consider the goal of actually stepping out into space en-mass: even my Skyhook infrastructure concept would probably need on the order of 240 gigawatts of electrical power to carry 60 million people into orbit annually. Even though that's only 1 percent of the world's current population, if we assume the human lifespan will eventually be extended to 100 years, everyone on Earth could get one chance to be an astronaut. All these people would be taken to orbit year-round on 300,000 - 400,000 spacecraft launches. You can't be serious about burning that much rocket fuel ?! The power should be electrical IMO. It's easier to generate, and has ultimately renewable sources like nuclear fusion and solar energy.

To provide 240 Gigawatts of power, we might consider orbiting fusion powerplants. Check out Lunar Helium-3 as an Energy Source. Helium-3 is NOT abundant on Earth, but is found in lunar soil in theoretically practical quantities, as described by the Artemis Project. There is enough to power the U.S. for 10,000 years, and He-3 fusion doesn't produce radioactive waste.