honestly you guys are kinda silly.
in ffxi when ppl did parties it was common not to roll on loot during a party i saw maybe 4 ppl do this in 6 years. same with the short time end game. You acting like ffxi was WoW which is worst.

every time someone did roll on stuff the leader would comment how rude it was and the player never lotted again or was kicked. So yes you can control lotting in pick up groups just make it one of the many unwriten rules ffxi had. Just keep telling ppl its rude to do it. It worked in ffxi.