Modern Tires

Like Rusty said, its all about liability. But I do agree that tires are not as good as they used to be. I just aired up tires on two cars that had been sitting for 30 years. First car all 4 aired up and 3 still holding two weeks later. Second car, three aired up but fourth was already off the rim.
The biggest concern with plugging a tire is where the hole is. If its on the sidewall or the edge of the tread forget about it.