This person told me her husband won’t let her eat pizza during the 9 days because it’s not an appropriate food for mourning. Anybody ever hear of that?
Klutz Chumra. The whole issur (as well as wine) is Zecher L’churban of Basar Korbanos (and Nesachim). (Shaarei Teshuva on Hil. Tes B’Av), which is why scotch (or beer, the example there) is mutar.
Of course, if you are an Am HaAretz (like this person you mention), you can make up any “chumra” you want.