Millennials Killing Mayonnaise

Once again, I never said those items don't alter the flavor. Anything you put on the burger alters or changes the flavor.
However there is a difference between complimenting and covering up

I don't dislike ketchup...I just don't like covering up the flavor of well cooked and seasoned beef. There are sauces that use ketchup that are very good....for example, Canes sauce is very good on a burger

I think a lot of people that slather on the ketchup and mayo didn't necessarily grow up with well cooked and seasoned beef. We're kind of spoiled now. Back in the 60's when everyone had a million siblings and one overworked mom, unless you lived on a farm you weren't getting any premium cuts, and were probably getting your food out of the freezer or out of a can. At least thats the impression I get from the boomers I know, who all LOVE mayonnaise.