When you look at history, this is what drove most human migration, although sometimes "profit" was just finding a place where food was more plentiful.

For every "Voyage of the Beagle," done for the pure joy of science and discovery, there were dozens of explorers looking for gold and spices. Nothing wrong with either of these motivations, really. Until there's profit to be made, I hope we'll still have people out there, same as we have them in Antarctica.

I can only think of two things which would financially justify an all out effort in space at this time: either the discovery of an alien ecology somewhere else in the solar system with an alternative biochemistry to explore and exploit industrially, or a cache of extra-terrestrial technology, perhaps a millenium-old Bracewell Probe, preferably intact. Both are long shots, to say the least.

An actual alien ecology would need to be approached with huge care, like an ancient and priceless scroll that is just inches from falling into fragments, and must be kept under controlled conditions. Nobody's going to be making money from that for a while, until it's understood.

I think there's some potential in tourism for near-term moneymaking. That could lead to other things. There is a LOT of wealth in the asteroids, but the tech will have to advance to the point where the initial investment is feasible. Eventually, it will be possible. The people who sailed the ocean in 1492 could never have imagined an oil tanker.

The great thing about exploiting space for profit is that, for a change, nobody is going to get booted off their own land in the process.