We always have a TON of side dishes (I even listed them in the other thread), largely because we have some folks who are casserole lovers, and others who very adamantly do NOT want their veggies disguised. I'm one of the latter. I have always had issues with textures, and there are many foods that I do not care for because of their mouth-feel. Most veggie casseroles are off my list, because I can't tolerate creamy foods that also contain crisp chunks, and I also have a low tolerance for cheese. That said, the four casserole-type dishes that are now de rigeur on our holiday menu are generally liked by a lot of people -- there are never leftovers. (FTR, the four are a spicier variation on the green bean casserole, a broccoli-cheese casserole, Spinach Madeleine, and a sweet-potato/praline souffle. I don't care for any of them.)
When I was a kid my mother was a typical Irish cook -- she either boiled, braised or fried EVERYTHING, and no two foods were ever mixed together except for the addition of butter and/or onions. As my siblings took over hosting holiday meals, casserole-style foods started to creep onto the menu, but the things Mom made also remained. (Mom really wasn't a very good cook overall, but she had a few specialties that she did VERY well, and most of them were either simple veggies or pork dishes.)
When I host, the veggies I make are essentially plain; with nothing but herbs and butter or olive oil added. If other people want to contribute casseroles, I'm fine with serving them, but 90% of the time I won't eat them.
The oddest holiday casserole I ever encountered was made by a boss of mine who invited me to her home the first year that I lived here.
It was some kind of jello mold that contained cinnamon, but it wasn't a dessert.