Well, America had something going for it, especially when reports came back from the early explorers that it's lush and habitable (in many areas at least).
On the other hand, people know what to expect from the rock that is Mars. If Mars was an unknown and people would want to go there to discover what's there, then the analogy would be correct.
Of course, people will still go, but reaching a critical mass for an unnecessary settlement (at which point it might turn slightly more alluring for more immigrants) remains to be seen. But I guess what happens happens, we'll see.
