McDonald's gave an exclusive contract for a particular ice cream machine. They then locked down those machines so only first-party repairers can fix them. It's a means of extracting wealth from the franchisees. The ice creame machine maker makes money on these service call outs so they have no incentive to make them reliable (the opposite, actually). And I'm sure McDonald's gets a piece of those service call outs.

Now does this do long-term damage to the McDonald's brand? Maybe. But nobody actually cares about that.