Many mormons are "preppers" in that their religion urges them to stockpile up to a year of food.
Well, those are the "annoying vegans" of the prepper world. That or folks using publicity to scare up interest and sell you things here and now.
Any prepper with an actual interest in long-term survival knows the importance of OPSEC.
I think you're experiencing selection bias.
You can (a) run away and watch them starve or (b) rush the compound and hope to get some food.
Threats -- and demonstrations -- of violence are only reliable if the person being threatened has something to lose.
If there's a 90% chance you die storming the compound, a 10% chance you survive storming the compound and obtain food and a 100% chance you die if you don't find food soon, why wouldn't you take the chance at survival?
I'm not convinced that people would be rational about their prospects if they were being shot at.