Coffee is a hot drink, and it can reasonably be expected to cause burns. However, McDonalds served its coffee at a higher temperature than anyone else in the industry and had been previously warned that their coffee caused more severe burns that would be reasonably expected.
Had McDonalds served their coffee at a temperature that a reasonable person would expect it to be served at, they would not have been liable for any burns caused by the coffee. This is why you don't see Starbucks getting sued for coffee burns.
McDonalds wasn't sued for serving coffee that is hot enough to cause burns. They were sued for knowingly serving coffee hot enough to cause burns far more severe than a reasonable person would expect and far more severe than the burns caused the coffee served by the rest of the industry.
Had McDonalds served their coffee at a temperature that a reasonable person would expect it to be served at, they would not have been liable for any burns caused by the coffee. This is why you don't see Starbucks getting sued for coffee burns.
McDonalds wasn't sued for serving coffee that is hot enough to cause burns. They were sued for knowingly serving coffee hot enough to cause burns far more severe than a reasonable person would expect and far more severe than the burns caused the coffee served by the rest of the industry.