Actually the term "Dixieland" came from the Original Dixieland Jass Band who recorded the first generic music.
The question of labels comes into play. Was Bix a trad jazz player, a "dixie" player or a variation of New Orleans (because he was influenced by Louis)? Well using so many labels, a lot of misinformation is fed about the music itself. As in the field of jazz as well as "folk", influences range widely and it's difficult to pin-point a style of music without referring to other influences outside that music.
Is there a real "Folk Scene" or is it a self-conscious attempt to recreate what is thought of as folk music for a small coterie of music enthusiasts?
As to the "stripey vests" and "garters on the arm", you only need to be reminded of those practioners of "folk" who dress in overhauls, wear funny hats or sun glasses to attempt to give their expression a visual validity.
Jazz is an amalgam of many different forms of music, classical, folk, ethnic, etc. The main thrust I advocate is that jazz is essentially an improvisational expression. There are those who disagree claiming that jazz "charts"...musical arrangments...constituted a jazz expression. I believe that there are those folk musicians who improvise thus making what they do a candidate for a kind of folk jazz. The blues players are one example.
So the Trad Jazz scene in the UK as well as the Folk Scene may be enclaves of people interested in certain musical expressions but whether they are actually representative of jazz or folk music is questionable. It depends upon how big you want to make the tent.
I submit that jazz is a form of folk music. If folk music is something that the people listen to and participate in, then Swing from 1930's - 50's could also be called Folk Music.
If Folk Music is an arcane study by folklorists and academicians, then certain preferences may establish a bias in favor of that kind of music.
The solution is to then go to the music you prefer to listen to represented by the artists who play it. The labels have a value to a point. But they break down when you analyze them closely. Most of the good that the labels do is point you to the right record bin in the store.