No, they don't get in a turn fight with them because they don't know how or when it's appropriate, although there are a few.
I must be pretty stupid getting all the kills I do in 190's turn/E fighting.
Fortunately for you, most people don't know how to turnfight in anything in the first place. Us sucky people like turnfighters because its easy to instinctively turn with them - not because we know how turnfighting works in the first place. We pull the stick, and voila, the plane's inherently better turning than the other guy's plane.. so we tend to think
"we're turnfighting!" - except we actually don't know what the hell's going on. We just pull the stick, and let nature take its course.
On the other hand, assuming you'd meet a pilot who's at least as skilled as you yourself, in something like a La-7 or a F4U-4 for example, I'd seriously doubt you'd try turnfighting with him when he's in a plane that turns much better than yours, and is as fast as yours (so you can't bugger out and dive to safety when things don't work out the way you imagined).
So you're not stupid. You're actually smart.
Picking a fight on the usual, clueless MA bottom feeders, and then outflying them in the worst area of performance on your own plane, is a very satisfying method to bolster one's own ego.
However I'd hardly choose such experiences as an objective opinion as to how one might manage a certain plane - you might confuse us sucky people when you say "I can turnfight in them", and then meet another seasoned MA vet in a better turning plane, and then do not actually turnfight him.
We tend to be misled.