Sure; a lot of people will never get into a small plane.
The worst example I saw was a date who almost got sick when seeing a picture of one, but then she was a proper
bunny boiler anyway
IMHO, in most cases you can't change it and I wouldn't try. A lot of people are petrified to get into a 747 but they force themselves because they have no real choice if they want a fancy holiday.
The "unsure" ones can be persuaded so long as you make it a nice smooth flight on a nice day, no tricks, no barrel rolls