Honestly, it's probably because 3Gun kinda ... well ... sucks in a lot of ways.
You spend your entire Saturday/Sunday shooting four or five stages and 99% of that time, you're waiting around and NOT shooting. Screw that.
You have to bring 6, 7, sometimes even EIGHT different types of ammo to the match?
The ranges are dirty, dusty, gravel-filled lots and always in remote middles-of-nowhere?
The entire shotgun portion of 3Gun is completely gamer-rific with almost no application for self-defense in the real world? Ugh.
And to top of it all off, you pay $20 - $50 just for the match fee, and YOU have to work the match to reset and paste targets. WTF?
I can see the disdain and the pain in the butt that these matches are giving you, and the best thing for you to do is to definitely take a break and/or never go back.
Stick to just pistol matches, 2 Gun matches, or go to a more regulated game where you actually get to shoot rather than sit around all day, like Silhouette or High Power.