hmm idk about the jelly. I let it slide if I get syurp on my ham, bacon, or eggs cause IDK well they were next to my pancakes. But I don't think I'd have a craving for such by itsself. Jelly on biscuits seems ok (I prefer butter) but I don't care for it.
I guess you can't knock it until you try it...even though I think jelly and cheese seems to....unnatural for me. It'd be like eating liver and onions or something.
You really should try jelly with a sausage biscuit! It's like a little breakfast sandwich and it tastes great! (McDonald's used to give you grape jelly automatically with a sausage biscuit, so I don't think it's that uncommon.) I love some maple syrup on bacon and you can even get maple syrup cured bacon that has the flavor smoked right in!
As for jelly and cheese, I think you might be surprised. My grandmother always ate jelly and cheese sandwiches because she hated peanut butter. I thought she was crazy until I ate it one day and realized that it was just fabulous.
My motto is, "if a lot of people like to eat it that way, it may not be all bad." (Which is generally why I eat food the way it comes in restaurants until I find out a way I would like it better!)