McDonald's uses unique machines that have two hoppers so they can serve both milkshakes and ice cream. More parts, more complexity. They also use a pump instead of gravity, so they can serve customers more quickly. That pump is probably what necessitates all these complicated moving parts, and makes it so much more prone to failure.

The video actually said that the Taylor machines at McDonald's were exclusive to them - the other franchises use a different model. (I'd wager the others are less automagic)

It seems clear to me that McDonald's is bad at training their workers to use the machine that other fast food restaurants don't have trouble with.

Makes you wonder what other shit like this McD has going on...