This is so true!
My husband had never even heard of Disney World before I met him! He grew up in a tiny town of less than 200 people in Montana, with no cable, and attended a one room school from kinder to 8th grade. He’s my polar opposite in almost every way imaginable, from our obvious physical and cultural differences, to upbringing and interests. However, I LOVE Disney and was confident that I could convince him to at least tolerate it, haha.
Our relationship went fast - he flew me to meet his mom in Montana 3 months in, and after that, I planned a Disney trip for the following year and paid for everything. I didn't want him to think about cost (especially since his closest basis for comparison were county fairs in Washington). I just wanted to get him hooked on Disney first. It could not have gone better! He's an engineer and was so impressed with the animatronics and all the other tech-y stuff. I went all out and booked the best restaurants, so he raved about the food everywhere. Now, 3 years and several Disney vacations later, he actually enjoys our Disney vacations. He doesn't like to go yearly because he prefers relaxing vacations, and I'm a park-to-close type of person, but we just do the cruises then (I got him hooked on those too! haha). I've gone to WDW and Disneyland without him a few times too, which is just as fun. I typically do different things when I vacation without him.
Honestly, if you do online dating, I don't think you'd need to use a Disney-centered site. Just make your profile reflect your love of Disney and I think that'll naturally weed out the staunch, anti-Disney/theme park people. Everyone else will know what they signed up for and will hopefully be open-minded about vacationing at Disney. That's what I did, at least.