Rick,
I know what your talking about. I think it all boils down to the reasons for their interest in the warbird of choice.
If you put it in the context of classic cars for example. When my father was alive we would restore classic cars and take them to car shows. My father and I were the traditionalists, we would want our cars to be as close to "Original" as possible. Trying to get them to look and run the way they would look and run when they came off the assembly line. Searching for original parts, radios etc. These guys would be your traditional warbird types with the military paint.
Then you had the hot rod guys. They chopped and channeled and leaded joints. Swapped out engines, bored out cylinders. They were all about performance and their own custom look. These would be your Reno guys.
Now I can appreciate both kinds and have participated in the creation of each kind, though as a lover of history it kind of hurts to watch a guy take a torch nice original '49 Mercury (or a P-51 Mustang).
But which ever you prefer, even in the classic car show world the "originals" generally are considered more valuable then the modified. This would be true for both the guy painting a warbird like a race car and to the guy who painted his civilian airplane in military colors - both cases they are no longer original.
As for the people who fly them. There again, you go to a car show and you'll see the guy in his bluejeans polishing his '30 ford and the guy parked next to him will be wearing his zoot suit and toting a toy Tommie gun next to his '30 Ford. Getting into character I guess?

(I'd be the guy in the blue jeans).
At least the flight suits have a purpose. They are safety equipment; though you will notice that most the performers and racers these days will now wear the same jump suits that drag racers and NASCAR drivers wear as they provide better protection than the standard military suit. The new ones are typically covered with "Sponsors" To me those look just as foolish as a zoot suit, but again they kind of serve a purpose. Both kinds keep the grease off you good clothes. I guess that's their best function. Warbirds leak

Oops Sorry, "Radials don't leak, they're just marking their territory."