Exactly - they're for emergency use only, to tide you over until you can get to a shop. I must admit that I don't get people who seem to take enough tinned food or food from home to live off for the duration of their trip For me, one of the best parts of travelling is the food.Most of the above items are extremely well traveled ie the stay in the van and don't often get used, typically only in cases where we arrive very late to pitch up.
I think our tin of cassoulet has been in the MH for almost 3 years/15k miles now - though we came close to needing it this year when our planned shopping trip on the Saturday before Easter was foiled by supermarkets closing early because of the holiday the next day (shame they didn't update their website with the revised opening hours )