Catastrophe - I struggle to see any commercial opportunities in Earth's moon or Mars, let alone any obvious ones. Exploration there is more about scientific curiosity and understanding than about economic opportunity and I support that kind of exploration. There are commercial opportunities to service those activities but that is not the same as the the moon or Mars having commercial opportunities in and of themselves, so it remains a subsidised, loss making activity of wealthy Earth economies, in large part undertaken for national prestige - a demo of the wealth of their Earth based resources and capabilities.
Can those explorations reveal unexpected commercial opportunities? It is hard to imagine what those could be - the very definition of unexpected - but we are no longer flailing in the dark. We have good understanding of the nature of our universe and solar system and how planets and moons formed, so we have some idea what is likely and what is possible; if we are chasing the unlikely and unexpected the moon and Mars may not be the best targets. Even asteroids may not be the best targets; they, like planets, have seen a lot of mixing together of primordial materials, whilst lacking the un-mixing processes that geologically and hydrologically active planets (Earth) have, that make the rich ores we depend on. If we want to find unmixed primordial materials - the potential for finding some of those precious metals or high value ores in more concentrated or more easily extractable forms - we may be better looking to comets or other targets that have not been subject to those mixing processes.
Exploration needs to identify real and quantifiable opportunities for the planning and investment any commercial exploitation to happen; people going to someplanet and expecting the opportunities to inevitably follow just won't cut it. The pre-investments needed are far too large for that kind of bet.
The best way forward for larger scale and long term subsidised activities in space may be meteor defense - maintaining reason to keep up space tech R&D that can lower launch costs and establish permanent orbital presence despite the absence of commercial opportunity. Greatly reduced launch and in-space transport costs, if they can be achieved, greatly change the threshold for what is viable - but those costs are so very high that there is a long, long way to go.
We may yet see some kind of high value zero gee manufacturing - something that (disappointingly) has not emerged to drive space investments.
I've suggested elsewhere that I think nickel-iron may be the commodity to keep in our sights. If some method that can get the precious metals out, that would be a bonus, but crude nickel-iron is hugely abundant and potentially able to displace mild steel for many applications. If it were being mined for Earth markets, with minimal on-site processing, there may not be human presence needed at the mine site but there could be a lot of associated space activity near Earth - supply to the distant operation, repackaging and de-orbiting the cargoes sent back - that could see people working in space to support it.