People don't need to make those decisions. Currently, safety decisions are made by the government, which really doesn't have any competition and thus is not incentivized to improve its set of regulations. If you had 2-3 companies providing market review for the passengers, I'm pretty sure the situation would improve, not deteriorate. Perhaps some regulations simply don't make any sense and do not improve safety, but you'd never know that until you have one agency managing it.
Airline safety is currently in a state where it is nearly indistinguishable from perfect. Accident rates are so low that it's no longer possible to put an accurate number on the risk of taking a flight. And all of this has been done while keeping ticket prices at extremely low levels. It would be remarkable for any change to this to result in an improvement, since there's almost nowhere to go but down.
