I agree with your chicken statement, but often times the reason people are unwilling to try something 'new' is because it may trigger some sort of feelings that they don't understand or aren't comfortable with.
maybe they had a chicken attack them as kid and they can't get over it.
on a bike you have to understand what's going on at all times, even as a passenger. some people just aren't ready for that, and may never be ready for that (most won't admit it though). I've met a few people like that, and there's nothing wrong with that. they're not ready for the responsibility then so be, I wouldn't want someone who had to be coerced into riding with me sitting behind me anyway.
I've met people who won't drive cars because they were part of incidents where loved ones were taken from them at a young age and they break down when pressured.
Saying people are 'ignorant' or don't want to try new things because they're not educated about it isn't always correct. Most people have their own personal reasons (and are not willing to go into detail, seeing as how you just met) for not trying stuff (usually they do).
Most people are also scared of death/getting seriously hurt. motorcycles, like it or not, are associated with death/serious injury. you don't hear about they guy who rode for 70+ years and was never hurt (especially on the news) do you? what the majority of people (non-riders) hear/see about motorcycles is the bad stuff. and most riders (squids and whatnot) don't exactly do good riders any favours. some people just can't see past that, and that's ok. I'm not gonna pressure anyone into changing their mind about it.
think about it: this person who just met you is putting THEIR LIFE on the line by sitting on that bike. they don't really know you, or how you ride, or even what kind of dude you are. it's not a pleasant thought for anyone really.
I wouldn't hop on a bike with what is pretty much a complete stranger either. I don't think most sane people would.