I can't remember which major brand it was, but they put out a "Homestyle" mayonnaise.
I may be wrong, but I don't think your average person -me, included- makes their own mayo...or ketchup, or mustard, especially if one has kids.
However, what DO you make from scratch at home, that most people would buy pre-made or in 'instant' form?
Cookies (except for Oreos)
Dips (onion, pimento cheese, liver, etc.)