I think the question was...why don't the low cappers/scratch players post their scores here. I would suppose that if they were already keeping track of their scores through the USGA handicap system, posting them here might seem a bit redundant.
There is a kid I know who golfs locally and shoots about an 8 handicap. I love golfing with the kid, mostly because I enjoy golfing with anyone who shoots that much better than I do. The one thing he has taught me is that one does not need to hit the ball a long ways to have a chance at shooting par or better. His drives average about 215, and he almost always has an makeable putt for par. I get quite a few chances to play with him because, with his junior membership, he needs an adult present to golf for free in the evenings (he usually shoots 36-54 holes a day, and he hates going home early). I've invited him to the site a couple of times mostly so I could keep tabs on his progress this spring when he plays golf for his varsity high school team (as a freshman). He told me he hasn't come here because he already keeps track of his handicap through the USGA.
Just a thought. And, yes...he plays from the tips.