From a discussion of the case (thanks Google)

For example, in a case in Pennsylvania, a woman also placed a cup of hot coffee between her legs and was burned when it spilled. The court—in dismissing the case—said in very legalistic language: “a purveyor of hot coffee cannot be held liable for burns sustained by a customer when an external force causes the beverage to spill.”

And further

The company further argued that it has sold more than 10 BILLION cups of coffee over the years and yet received very few complaints. It admitted it has strengthened and tightened its styrofoam coffee cups and stamped a warning on them, a warning that its competitors have not done.

It further admitted—and this may be the reason for the huge punitive damage award—that it had not reduced the temperature of its coffee, and has no intention of doing so, even though it has known since 1983 that people were getting burned from spilling coffee. McDonalds said more than 700 persons have been burned at its stores, most from hot coffee. McDonalds called that figure “statistically trivial.” A witness for the plaintiff called that remark “corporate callousness.”

McDonald’s also admitted people over 65 are at an increased risk for coffee spills. It admitted that its coffee-drinking customers are probably not aware that they can get 3rd degree burns if they spill coffee on themselves, especially if they cannot escape the hot liquid within a very few seconds of the spill.

Stella said she saw a warning on the cup: “Caution contents hot,” but said, “What you don’t expect is a cup of coffee to be so hot that it would burn you.”

Sorry, my reasonable man inside me says 700 out of 10 billion is NOT statistically significant. The "callous" remark was inflammatory rhetoric by the plaintiff's side. Even 165F coffee will burn you.

So 1) reasonable man - no it's not unreasonable to serve a very hot product, it's made from boiling water. 2) Duty of care - injury rate of less than one in 10 million is not significant enough to compromise its way of business.
3) Proximity - McDOnalds printed warnings, stiffened their cups - not sure how much more they can do, other than compromise and make their coffee crap. As Starbucks will tell you, that's not a path to improved quality.

So, thank you for the discussion, but basically, we disagree on what is "reasonable:. That's why there are juries. Hopefully they are swayed by logic, not appeals to emotion and painting corporations as the big bad wolf.