I think it's like all blue ocean endeavors, like Columbus first trip.
He used the wrong earth circumference calculation to estimate his trip to the Indias to convince the queen (it was way off, that's why the Portuguese went around Africa instead), he got really lucky, and the end result was way better than what they set up on to obtain in the first place.
Exploration is a bit crazy and a bit stupid, some people die and a few times we find something amazing that was in non way near what we thought we would find.
I think Mars is - hopefully - going to be a bit like that. We go for one (maybe the wrong) reason, yet we stay for a different one.
The mortality for interplanetary spaceflight, in the near future, will likely be an order of magnitude lower than it was of the Age of Exploration’s front line. The comparison is terrible for several reasons. But it’s one that speaks to spirit, not means. If the Americas were uninhabited, they would have been—to colonial-era Europe—of comparable difficulty to setting up a permanent Lunar or Martian. (Note: NOT permanent population. Reproduction is harder.)
> Americas have trees, meat, rivers, oxygen, grasslands, forests, birds
Exploitable constrained human power shipped across a sea by way of a costly, lossy transport system. Colonising the Americas without a latent labour pool and social hierarchy to swap over would have been near impossible for pre-industrial Europe.
It would have required long-term support across months of shipping and communication time for purchase of unknown resources in unknown time scales in respect of unknown risks. Sound familiar?