I've spent a significant amount of time working in disaster response. In the US (and probably elsewhere), you have "Disaster Cowboys." These are people who are untrained but fancy they know better how to do things than people who have spent their lives training for these types of scenarios. Picture 1000 people showing up with their pickups and John boats following Hurricane Katrina. Or, imagine the Coast Guard conduc…
We call them Walter Mittys, not Disaster Cowboys, but yes, these people appear at every scene. Everything else you said rings true, but sometimes motives are more sinister than a desire for personal glory. Vulnerable people attract predators and there's plenty of vulnerable people in disaster zones.
Funny you say that, because the government wants a monopoly on "help" and is willing to use lethal force to enact it.