so you're gatekeeping the descriptive "genre" of First Person Shooter

Other way around: I'm not letting you smear my beloved RPG by incorrectly labeling it an FPS lol

and in whatever definition you have you exclude all the games that don't mainly focus on first person shooting,

You know what a genre is, right? Would you call the Horizon and Assassins Creed games platformers? They involve platforms, after all 🙄

despite the fact that first person shooting is one of the most common ways to progress in the game?

It isn't, though. One of the things that makes it a better game (in my subjective opinion) than for example the Diablo games is that there's tons of other ways to progress than just shooting everything.

the definitions of what fits or doesn't fit a certain genre depends entirely on the audience's opinion

Nope. People are often objectively wrong about things.

go ahead disagree with the leading opinion

Thanks for the permission to keep not having my opinions determined by the frequently ignorant masses, I guess. Am I also allowed to keep refraining from saying "literally" when what I actually mean is "figuratively"?