Ultra fancy engraved firearm in an ultra fancy leather rig worn with high dollar hats, suits, and cowboy boots by rich people attending exclusive BBQs. Not being a rich person I have never had the chance to see if this is really true.
Well, first, we have to understand what a "barbecue" is in this context.
From my personal experience (and family experience as related to me), the use of "barbecue" in this context is to mean "local event & gathering." It is probably related to all the meanings of
barbacoa in Mexican Spanish. So, not merely the slow cooking of the meat, but also the gathering of people to share in both the cooking effort and the consumption of the end product.
Out in the rural, agricultural areas, opportunities for social gatherings will take second fiddle to the work at hand. So, if a windfall were being celebrated, or, especially and anniversary or wedding, would want having a "barbecue" (even if the food was not smoke-cooked). And, as noted above, these would be
Occasions. Something wanting the Sunday-go to meeting, attire. The kinfolk and relations would be brought in as well--in many ways a ginat shown-n-tell.
Now, while "fancy" can apply to firearms, it's not required. Fancy leather is not required, either. But, if one had such to show, no one avert their eyes, either. The notion is to be respectful of all, so, no jamming
El pistole under the belt, of jammed down one's jeans. And, being able to show off that fancy belt holster from the tack shop or boot maker is always good.
To the question of "Why would I want to be armed at a barbecue?" one ought remember that these evolutions were far out in the country, where land was measured not by the acre, but by the Section (square mile; 660 acres). You might be traveling half a day or an entire day away from a major city; and be hours from even a small town or hamlet.
Having been to several of these sorts of
soireés, the Court guns and Trusty-made holsters do appear. But, that's often just the LEO and Court Officers, with the access and need. Plain blue and oiled russet leather will suffice nicely. Or an El Paso Tom Threepersons floral for one's 6" blue Python.