I knew you'd hate this and would drag out your 'supporters are clueless scum with no power whatsoever' soapbox.
The plan had nothing to do with it, the issue was that there were simply too many participants who weren't that committed especially when the local associations and supporters pushed back. There is no plan that would mitigate that risk, they simply had to hope that it wouldn't happen. The mistake was misreading the commitment of the participants, not the lack of a plan.
And the reality is that a lot of the participants really do care about the views of the local associations and the supporters. No matter how much you hate it.