FR is for nutcamping, 6max is real poker.. my opinion ofcourse

(little explanation: in FR you have 8 free hands per cycle, in 6max you have 4 - so in FR there is very little incentive to act. This would be completely different if there was, for example, an ante. Or in MTTs/SnGs, they raise the blinds to force you to act, a thing that is non-existant in FR. So this favors nutcamping. Another thing is that you have 9 opponents as opposed to 5, so the average hand you get is of less value - more people means higher chance someone got a good hand)