What Chris said — but I'd add that it's not so straightforward to swap between NSF and Experiment. The budget for a typical NSF proposal is much, much bigger than most folks are able to raise through crowdfunding platforms — they usually supports people's salaries or graduate student stipends, and sometimes major equipment purchases. Experiment gave us enough funding to get the genome project well underway, and it helps us demonstrate to NSF that a lot of people care about Joshua trees — so it's a good first step toward the larger project.
Well, I think most people whose pre-proposals are rejected use the reviewer comments that they receive to revise and resubmit in the next year — or come up with a totally new project to submit instead. (I've done both, really.) But I'm sure there are projects that never get resubmitted.
This would have been, I think, the fourth pre-proposal I've been involved with at NSF. That portion of the process wasn't necessarily bad — it's kind of nice to "pilot" an idea in brief form before putting in the time to build a full detailed proposal — but the whole two-stage process was slower than it used to be, with just one opportunity to submit full proposals each year. There are, apparently, some possible changes in the works, but I don't know what details of those have been decided on yet.