This is definitely the truth. There I so much chest thumping and bs'ing going on around cave country in Florida. From my experience the ones doing most of it aren't really the ones doing the real dives. Very few cave instructors are the ones doing the real exploration. You don't realize this when you are a new cave diver but as you gain experience and start going to the end of the lines in the various cave systems you generally don't see their line arrows.
Personally, I hate seeing glory markers.