I'd much rather visit an asteroid than Mars, so I agree with you there - but I think there are other ways that Mars may become attractive to settlers - especially those who want to escape tyranny on Earth. If a settlement starts and survives, then whoever gets there and participates is literally building a new civilization from scratch. I think you might be a little naive in thinking there aren't a large number of willing people who want to do that, no matter the personal cost. There's a lot of potential.
The problem isn't the individual, its the society that has to pay for it. We can find the exploration of Mars a worthwhile thing in the abstract. But as a society that interest will wane in the face of the reality. Then we aren't going to be paying billions to ship misanthropes off to Mars to thumb their noses at us.
