Since Miracle Whip (in my existence) was always called a "Salad Dressing" even though it had the consistency of Mayo, I guess I miss the reason for the controversy.
We traditionally used it primarily as the base for cole slaw, potato salad, tuna salad, macaroni salad etc. Many cole slaw recipes made with mayo say add vinegar and sugar and spices to the mayo (so essentially making diy MW). Google shows potato salad recipes, a fair bit include vinegar and sugar with the mayo. "Salad Dressing". Miracle Whip is just that in a jar, mayo with the other stuff pre-mixed in it. We used it on BLT's and tomato sandwiches exclusively. I don't use regular mayo on sandwiches, it's mustard or nothing; but that's just me. I live in a household that likes Hellmann's/Best, but I don't use it.
I eat ketchup ( I pine for the old Ann Page ketchup, I don't know who made it for A&P but it was good) only on fries. I'm American-style no mayo or ranch please. Never add it to eggs. Hot sauce is another thing though, but that started when I moved to the SW.
We did add yellow mustard to potato salad, French's I believe. I think that's a regional thing.
Now Tartar sauce, ugh, what's up with that stuff?