I quite agree that the argyll jacket was perfectly appropriate for the event--nice looking jacket, by the way. Those wearing PCs were likely doing so because it's the only kilt jacket they own. During the many years I spent in Scottish/piping circles in and around London, Ontario, I encountered many kilt wearers whose only jacket was a PC. They bought their kilts to wear at Burns dinners, Masonic or Shrine events and other formal occasions where a PC would be appropriate. Few of them ever wore their kilt in other circumstances and felt no need of any jacket other than a PC even if they knew, which few of them did, that a PC is not appropriate for all occasions.