Yeah I don't get it either, for the same reasons. All I can think of is... I worked for McDonalds back in the 1980s. They had soft serve and milkshake machines

Yeah I don't get it either, for the same reasons. All I can think of is... I worked for McDonalds back in the 1980s. They had soft serve and milkshake machines then, but they were simpler. They almost never broke down. I do not recall any breakdowns in fact. The machines did not have an automatic pasturization/sanitize cycle. They had to be taken apart, cleaned and sanitized every night after closing, and then put back together the next morning. That took an extra person on the closing staff just to clean the machines, and another person the next morning to set them back up. Roughly two hours of labor a day, every day, to do those tasks. An experienced person could do it faster, but that's a ballpark. So McDonald's was betting on the labor savings offsetting the costs of the newer, more complicated and less reliable machines. Overall that may be working out on paper, but the perception of soft-serve being "always broken" is something I am surprised that McDonald's tolerates.