I call it "trusting gravity a bit too much". I developed some anxiety about driving in mountainous terrain back in '02 and it rears its ugly head sometimes. We were driving down from WA to CA, and as we were going through the passes, even though the driver (sometimes me, sometimes DH) had perfect control of the situation, I kept feeling like gravity was just going to draw us over to the edge of the road and plummet us down. 'cuz gravity controls steering wheels ya know.
If it's important for you to ride, I'm sure over time you'll figure out some tricks to help you. I get a bit nervous during the film sometimes, and I find that being in the middle or bottom helps because seeing the feet reminds me that I'm NOT actually hangliding. And I look to the right and left of me, to remind me that everyone else in there, including 4 year olds is having a great time, no worries, no one is going to fall out. That's my trick.
But if it's not important for you to ride it, then forget it and be happy to not deal with the lines!
Well, over at Universal there's a non-moving section for Jimmy Neutron, and considering just how much movement there is in the regular section, one might wonder "why bother", but there were people lined up to sit there, so....
Or at
Disneyland there's the non-submarine viewing room for Finding Nemo where you just watch the movie...
So they certainly *could* have a viewing room, and I'm sure there would be some that would enjoy it.