RE: Could one accident ruin the hobby?
I'm with Gordon... I can see how a serious accident could hurt part of the hobby. A turbine jet goes in, sets fire to a patch of grass near a chemical plant or whatnot, and the next day's headlines run: "Flying firebomb strikes: you could be next!". You can be sure that there will at the very least be some new rules and regulations for Jet flyers after that.
On the other hand, look at things like car rallys. Quite often a car goes off track and plows through the spectators lining the road. People have been killed... yet there are still no bans on rallys or even rules about how close the spectators can be. Politicians aren't always the rule-crazy zealots that they appear to be, and they're often willing to take common sense into consideration, separating the 'bad luck' accidents from the mishaps that can be prevented with rules.