do you mean why did the paint fall off cars in the 90's?

the biggest reason is because the manufacturers didn't put enough paint on the cars.

with not enough paint on the car allowed the ultraviolet light to penetrate the chemical bond between the sealer and the color coat. causing the color to de-laminate between the 2 coats.

i have painted thousands of cars with that problem.
at a high volume dealer body shop i probably painted at least 10 completes a week for 5 years.