M.Mouse
Good question, it's never happened to me but I take your point and accept many don't know or care what they are bording. I guess being one of those people who do take a keen interest in which type of aircraft I'm flying on, the 'oh I've never flown on a 777!' novelty factor might overcome the 'oh no it's a twin', who knows? I'm not paranoid enough to balk at the gate because of a change of aircraft but that said I do book flights based on aircraft type.
For the record I wasn't trying to suggest that twin's are fundamentally unsafe, more that I have a personal preference regarding the number of engines. My comment is related to market forces than anything else. A number of posters seem to be forecasting the demise of the 4 engine due to economics, particularly across the Atlantic, I personally believe that whilst costs obviously play a huge - most would say the only - role, market forces also contribute, if this wasn't the case we'd never have heard of "4 engines for long haul" and it wouldn't have emblazoned the side of certain aircraft. I think when they painted that on they weren't trying to attract pilots but people like me?