Are there any big payoffs that would provide incentive for private industry to explore Mars? Not that we know of yet. Although Elon Musk has said he is interested in going to Mars, and the as yest unbuilt Falcon Heavy rocket has significant payload capabilities, the financial incentive of sending people to Mars is far outweighed by the costs of such a trip. Thinking of space exploration in baby steps might be a better path. Start from Earth, build a space station, build a moon station and harvest fuel there. Then build your Mars launchpad on the Moon (with much less gravity to overcome). We also should be able to orbit asteroid for harvesting. If all that happens in the 50 years that would be remarkable.
A good article on some of the challenges in exploring Mars was posted here. It’s pretty thorough and an enjoyable read.
This piece from a paper in Houston puts some perspective on the comments made by Neil Armstrong and Gene Cernan about SpaceX. The comments down below show some disagreement by space enthusiasts about who’s right. I’d say not knowing SpaceX’s financial backers makes me somewhat curious as to their motives, but not to the point where I distrust them. I think Cernan and Armstrong are right to wonder how SpaceX is going to generate funds and if their launch manifests remain full how soon will they be a profitable business. Cernan and Armstrong come from a time where NASA had its focus on doing new challenges for the sake of science and political impact (Kennedy wanted the moon landing). Now space exploration comes from a business that wants to make it profitable, not necessarily cheap, though it may be cheaper than NASA could do.