But then I thought, could it also be that most people have jobs and are unable to train optimally?
Americans love powerlifting. Most people can relate to the bench and the squat and the deadlift. Anyone can walk into a gym and perform any of these 3 exercises with very little instruction. They take little to learn as they are not technical, just brute force.
Americans love football. Most football players do powerlifting to train for football. A few athletes will do the clean, but usually the power clean from the hang with poor form catching the bar and poor range of motion and they rarely add the jerk.
Few high schools and colleges have anybody who can teach the lifts. Most strength coaches know what the clean is (usually the power clean) and will use it, but it usually ends there. A few strength coaches will do the snatch, but usually in college. Very few high schools have strength coaches and even fewer of them (college and high school) are USAW certified. Most strength coaches will be a CSCS but there is no proficiency in both O-lifts to be a CSCS.
There are very few meets. And when there is a meet, there is little interest.