I agree that on a properly fitting feilidh-beag (i.e. firmly but comfortably snug at the waist), using the loops for either a belt or a sporran is optional and I personally have recently taken to not using the loops depending on how I'm kilting up at the time, and sometimes not even wearing a belt. Of course both the original feilidh-beag and feileadh Mhor had no loops, so there you have it. To each his own.