Gee, now I believe I've heard it all.
A liability issue? Come on now, isn't that being just a little over the top? What else will you stoop to in order to get your way? A stance restriction is a very simple thing. ONCE YOU GET SET, YOU MAY NOT MOVE YOUR SUPPORT POINTS! Kind of the same as not grounding your club. SIMPLE! If you play ball golf and land in a sand trap, you may not touch the sand with your club until you swing at the ball. SIMPLE! If you are playing with your buds for fun, whack away at the sand, who cares? If you play on the PGA tour and land in a sand trap, mind the rules or you're gonna get called. SIMPLE!
I can hear it now, "Hello, Mr. Lawyer, I want to sue someone because I twisted my knee when the TD said I had to follow the rules. The PDGA doesn't use these rules, so the TD can't tell me how to play the game. I knew the course rules before I started, but I don't care for this or that, so I want justice!"