I’ve long suspected part of the issue is the franchises not following properly cleaning and maintenance guidelines with them, leading to higher failure rates. I know McDonalds sells more ice cream than basically any other fast food place, including actual ice cream joints, so the same issue for them will likely cause more downstream failures than it might for others just because they’re working the machines harder.

Anecdotally I know in the McDonalds near my old apartment the people would say the ice cream machine was broken in part because they just didn’t want to have to clean it. So they really would prefer if people not order ice cream.