I was paxing on a flight in the United States when we had a very rough approach on the fringes of a tornado to Birmingham (Alabama) we diverted from minima all the way to Florida. A quick fuel stop and away we went minus 6 of the 45 other passengers who refused on grounds they felt it unsafe to fly in such conditions.
I dont see how you can force people to continue on the aircraft in such circumstances.
Of course a panic attack, sudden onset of fear of flying or similar should do the trick nicely if ever detained against your will.