If this coffee is < 200F, then I can safely put in lap. Else, I will ask nephew to hold.

Nope. People don't do that. They just do the right thing most of the time, dumb things a small fraction of the time. Some people do more dumb things than they should.

The Liebeck situation is an edge case. McDonald's sells tens of millions of cups of coffee a day (depending on the source, 10 million/day or 300 million/month or 500 million a month). If there are several burn cases a year, or even several hundred, that probably does not constitute a significant trend.

There are thousands of people who burn themselves, electrocute themselves, crash their cars, choke on a bone, and do other things that are unfortunate but avoidable with a little common sense.

You can't protect everybody from every contingency, nor would you want to; we would become a nation of prisoners in soft rubber cells, protected from every possible danger. I read a sci-fi story about that once and it was rather unpleasant!