Coffee snob here. I once talked at lengths about how great specialty coffee is, the breadth and depth of flavours, the intricacies of extraction, etc. bla bla.
When i was done, he just looked at me and said “you know, sometimes when i get to work early in the morning and there is still left over coffee in the machine from the day before i just poor it in in my mug and drink it”
So yeah i think one day old, stale, cold, cheap supermarket coffee is up there i think. I don’t think you need to be a snob to find that offensive