"We'd pick them out of the ocean, but we spent a lot of time cleaning those things up when we got them back"
And there's the rub. SpaceX is working on having reusable components land on solid ground.
And there's the rub. SpaceX is working on having reusable components land on solid ground.
The meat of the 'argument' (and really, I don't believe it's an argument) is that the Shuttle Main Engines (the ones mounted on the tail of the Shuttle, the ones that land like a plane) had similar expectations of reusability, and ended up being absolutely terrible at reusablility. That's the point to address, not the throw away line.
Another consequence of the LH2 choice for the Shuttle is that it didn't have enough thrust at sea level to get off the pad, so it needed high-thrust, low-cost boosters as a 0th stage. Solid rockets being the obvious go-to solution, those got used.
In a very real way the choice to use LH2 resulted not just in much of the cost and complexity of the Shuttle system but also the death of 2 crews and the loss of 2 orbiters.
The methane direction SpaceX is taking going forward strikes me as almost a no-brainer. It gives you a higher isp than kerosene, is about as easy to handle as LOX, and is super-abundant and cheap. In addition to being basically 95% of natural gas it can also be made electrochemically/thermochemically from water and CO2 or trivially obtained from biomass digestion. The latter options are all possible on Mars. It's also a renewable fuel if you get it from non-fossil sources on Earth.