In order for it to work, it requires a concerted effort. It would be perfectly acceptable, if for example, several years of supplies had been stockpiled at the landing site in advance, in addition the plan would be for the first arrivals to work on creating the infrastructure to support successive waves of people making the one way trip. Once you get enough gear, and enough people (labor) there, its possible to the colony to start being not only self sustaining, but self expanding.
I think you're also overstating how "rich" the "New World" was for the first waves of colonists. Due to a lack of knowledge, plenty of them starved to death. We have the advantage of enormously greater technology. We can be extremely confidant that starvation won't be a risk.
Granted, there's a big "What if?" there, that IMO is fairly critical to start exploring. We know that people don't handle effective zero-gravity very well for prolonged periods, but we have no data at all on the effects of prolonged exposure to gravity much greater than 0G but noticeably less than 1G. How about reproduction in that environment? Again, we have no idea. That's another task the first colonist(s) should be tasked with: animal studies of reproduction in reduced gravity. If mice and rats can handle it just fine, then full speed ahead! We could have native born martian-humans within a few decades.