Strange! I go yearly and I've almost always been able to customize there. Actually, the cashier asked the person in front of me if they wanted all the toppings. The previous night I got the Banshee dog but they ran out of chili and so I asked if I could just have it without the chili and they said yes, so I was very confused.
No offense to the chef, but they're losing out on massive sales by cutting out various demographics from trying their special fare when they don't allow people to choose how they eat their food. Obviously a lot of customization requests are set to cater to allergens, dietary restrictions, or in some cases belief systems and are not super difficult/annoying (I.e someone who can't eat cheese due to lactose intolerance or a vegetarian eho wants the item sans meat). It would be different if I were to ask for a Flying Dutchman (the fried pickle) sans pickle or coating, Because it's the entire item!