I actually like the weird feeling you get in your stomach on drops that you so hate, but I know exactly what you mean. Anything remotely spinny means my tummy's going to be unhappy all day, and I just hate getting banged around on rides. I used to ride roller coasters a lot when I was in my teens, partly because I did like the drops, but mostly because I got paid to accompany the kids who couldn't ride by themselves.

But at this point you couldn't pay me to do it!
I really like Lynne M's point that it isn't really a phobia -- it's that it's plain old uncomfortable! There is a reason good doctors and nurses will
ask you how things make you feel or if things hurt and how much -- we're all wired differently! The fact that one patient isn't bothered by something tells them just about nothing about how the next person will react, and the fact that your kids or spouse like something doesn't mean you will, either!
Personally, I view this sort of thing as yet another opportunity to teach my kids that everyone is different, that everyone has the right to their own likes and dislikes, and that it's not an insult or an act of disloyalty when someone doesn't like what you do. I'm always amazed at the number of people who reach adulthood without realizing that. Partly because I'm related to some of them.