I don't know what makes you so certain that general sentiment is anti-McDonald's in this case. I have only ever heard the story given as an example of the frivolous lawsuits brought by overly-litigious Americans. It makes a good example of that ("they sued over hot coffee?"). The alternate framing, that McDonald's made coffee too hot, doesn't make for a very noteworthy or pithy story, so I'm skeptical of your take on the public opinion.