Before I say anything else, I want to say that if a group of friends is having a good time playing with their toys, I couldn't be happier. Do your thing.
But having seen this same thing in a number of gaming communities over the years, let me assure you- they aren't playing BrikWars from the rulebook. They're in a midway stage between free imaginative play ("Pew pew! I shot you!" "Nuh uh, you missed!") and the more structured mayhem that your... more fully... umm...
I'm trying really hard not to use any language that can be construed as pejorative, because again, no judgement, but the correct term is mature. They're just starting to grasp that freeform imaginative play is less satisfying in some way than it used to be, and they see others having more structured fun that looks a lot like the fun they used to have. They know they want in on that but just kind of skim the rulebooks, adopt what seems fun, and make up a bunch of other shit.
And again, I don't think that's wrong or bad. I still hate slogging through a rulebook for the first time. It's my single biggest impediment to getting into ANY game.
The group will fracture as some morph completely into gamers, whereas others don't have the temperament or interest and move on to other hobbies.