I was at Cimarron Hills Country Club in Georgetown a few years back, touring the golf course a month or so before it opened. The head pro tossed me a club-branded ballmark repair tool, and said that members of the club would be required to take a class on fixing ball marks before they were allowed to play. Yes, even after paying their sure-to-be-hefty dues. I don't know if they've stuck to that policy at Cimarron Hills, but more clubs (and public courses) should have this requirement.
I was reminded of that episode by Grouchy Golfer's post, Fix That Ball Mark Properly!
Only a small percentage of golfers repair ball marks. Most golfers don't repair any - their own or anyone else's. And some golfers want to do the right thing, they just don't know how. So they keep "repairing" ball marks when in fact they are just tearing up the roots of the grass and causing further damage.
The folks who do it the wrong way generally try to "pry up" the middle of the pitch mark, bringing the grass back up level with the edges of the mark. Wrong. (But at least they're trying.)
The correct way is to insert the tool at the edge of the ballmark and press or gently twist forward, moving the grass toward the middle of the "crater." Here's a refresher course on ballmark repair.
(Image from Golf Course Superintendents Association of America)