I just played a match against a guy who has 35000+ kills with the FAL and the next most used gun being some gun with less than 500 kills. He told me he just found his go-to gun early and he didn't see any reason to try out other guns. He also told me using the FAL+select fire makes him a hipster because the full-auto FAL has high recoil and because it's not a SMG. Have you met anyone like this before? I know it's just all personal preference but I just can't understand how this is ever fun.
I guess that's kinda how I was with the 74u in black ops, something like 30k kills with it. with a few others in 10k, total kills above 100k. While it was my go-to gun for when i wanted to win, I couldnt use it ALL the time. If he's happy with doing that, that's fine.
I had 150,000+ kills with the spas12 back in BO1, but of course that was acquired over 2 years of playing nothing but demolition. When you find that gun that just clicks, its hard to not use it once you are so used to it.