Earlier quoted context omitted.
Isn't the same machine used for milkshakes? That's kind of staple of burger joints.
Yeah, but the point is that MacDonalds obviously doesn’t want to sell icecream. Maybe it’s low margin. Maybe cleaning is expensive. Maybe it helps having the promise of cheap ice cream but “sorry not right now” leading customers to buy other (more expensive) items. It’s not an incompetent organisation. If they wanted the machines to work, they would work. They don’t. So… if anything changes out of this, it will be to…
If anything, ice cream products represent a very profitable item that often serves as an upsell helping drive the APV (average purchase value) higher.
Milkshakes in particular have a unique "job to be done" in the drive-thru fast food industry: https://hbswk.hbs.edu/item/clay-christensens-milkshake-marke...
They can be eaten easily in the car, can be savored slowly over time on a long commute, and are relatively filling and inexpensive. There are a lot of people who actually consume them earlier in the day before work because of those characteristics.
You'll notice that basically every burger chain offers milkshakes, and some even emphasize the shakes more than the food, like Shake Shack, Dairy Queen (which has quite good fast food burgers and food if you aren't aware), and Steak 'n Shake. They all do this because it's an extremely profitable product and a driver of high APV.
The ice cream machines at McDonald's also deliver multiple products: McFlurry, hot fudge sundae, milkshakes, and ice cream cones. One small machine that dispenses vanilla soft serve can make a whole bunch of products.