I doubt they make more from repairs than by selling ice cream made by functional machines.

True, but ice cream is expensive. Soda and fries are cheap. Burgers and ice cream get people into the store where they buy soda and fries. And I’m sure many a person has gone to McDonalds wanting ice cream and upon learning the machine is down, decided to get a drink and fries instead.

I haven't seen any actual evidence that Taylor is giving kickbacks to McDonald's. I've only a lot of insinuation and accusation of such a kickback, because the accusers don't seem to consider other possibilities. One possible reason other than a kickback: McDonald's wants the machines to error on the side of food safety and don't trust their own employees to not fuck it up.