How accurate is HD ratings like OFA, PennHip ?

Gonna start this one by saying that PennHip is expensive. OFA does not require that the results be sent in. I want you to think about that for a moment, and how these basic ideals will effect the overall outcome. OFA does not require results to be sent in. So, you go to the vet, get your x rays, and then you pay another 45 dollars to send in the results. Easy right ? Well, what percentage of people who get bad news don't feel like spending the extra money ? What percentage see that their dog has really good hips and that is good enough for them ? And finally, how many people get their dog x rayed if the dog is not limping/hurt ? So, just with OFA we can see how the results can be effected so easily. 77% are normal according to OFA, which can only base it's statistics on what is sent to them. PennHip also has a problem. Being that it is more expensive, usually by a lot, people are getting x rays to see if it is even worth spending the money. Many breeders go to OFA or SV first to see what the hips look like, and if the hips look good, will go ahead and spend the money. Again, the results are skewed, because while you have to send in the results no matter what, people cheat the system and will do the cheaper hip rating first before spending the money. This is something I think about a lot, because I go and look at the databases, and hardly any of the puppies I have sold have gotten hip ratings from OFA or PennHip. I suspect this is pretty normal across the board, but of course, I am not sure. What does this all mean for the future of the breed ? Not really sure.