The daily creel limit is never exceeded in tournaments, so is it ok for everyone else to keep their fish and not tournament anglers?
If you're referring to the 3 fish limit suggested above, then it's more about making the sport more appealing to outsiders. I've been to many ramps the next morning after a tournament and have seen dozens of floaters.
Most of the smaller tournaments that I fish on Nickajack are 3 fish limits.