Because most games are age restricted. Kids shouldn't even be on cod but as well as maturity level most people act immature AF.

^ He said it the best !

There are so many kids said to me they slep with my mom.

It don't really matter to me what age you are. If your a good player and not annoying or seem like a dick then I will probably play with you. I don't care if they are a sqeaker or have a deep voice as long as they are chill. To me most people don't like little kids on games because they are just completely arrogant and annoying as shit.

But like I said if they cool I'm cool. So pretty much if your a little ass kid and what to play or be accepted by older gamers just be more mature.

Right lets be honest, for example, Call Of Duty is not made for kids, there's an age restriction on it for a reason, and it's because you shouldn't be hearing that language or seeing graphic scenes.
Yes, there is no way to stop you, however the age restriction is there on the game to advice your parents when buying the game what age it is actually suitable for.

As far as the events come, you can have immature kids, and let's be honest again, most of them are mature, running around an event.

I personally don't mind personally as long as you don't get on like a complete moron, however, I don't create any games or host events so yeah, outa luck

Due to the fact that they're playing the game at a really young age, I have no problem with a 14/15 year old playing an R game, but a 12 year old kid can get really annoying.