The dangers of... hot coffee? Yeah, everyone knows that. That's exactly why they shouldn't have lost to the extent that they did.
It's tragic for the person involved obviously; I get why emotionally the court would feel sympathy for the victim. But objectively speaking its pretty ridiculous for the legal system to be awarding punitive damages for companies exposing people to normal, reasonable risks that everyone encounters as part of everyday life. It creates a culture where businesses have to treat grown adults like children for fear of huge fines if something goes wrong.
At worst McDonald's was probably like 10% responsible for the incident but they got treated like they were 100,000% responsible.
(The jury actually did find the woman was partially responsible, it was the judge that decided on the absurd damages amount. It later got reduced and settled out of court so all in all I think the system ultimately worked okay despite the judge's ridiculous initial decision.)
Edit: I misread, it was actually the jury that made the initial ridiculous punitive damages ruling, the judge was the one who reduced it later before it got settled out of court for an undisclosed (possibly still ridiculously high) amount.