There is nothing more frustrating than a parent who clearly has no clue what their child is up to. When this spills over to the online gaming universe, the results can be negative and border on dangerous.
I play a lot of multiplayer games live. I am very aware of the kind of people and conversations that take place online. They really are just about as scandalous as one might assume. Players online (myself included), have glaringly inappropriate language and conversations. If you are not there to monitor who your child is talking to, they are exposed to direct interaction with these people.
Children are also at risk of picking up these bad words and habits. Many adult gamers have listened to screaming children of admittedly young ages. Shockingly, these kids are using words and phrases that make grown men blush. Kids throw out racial slurs, sexual comments, and gratuitous insults. I'm sure that most parents think their kids would never do such a thing. But I assure you that once the guardian has left the room, they are just as verbally aggressive as most of the adults.
Lastly, your kids are annoying ! As adults, gaming online is a quick, fun, social outlet. Unfortunately, kids show up and ruin everything ! They yell, scream, call out to their friends, answer the phone, and play their radio all without muting their mic. While we do have the options of muting people, it simply becomes tiresome to mute a person who is too young to be playing in the first place. They are not mentally mature enough to socialize appropriately. And worst of all, muting doesn't always work. If they are loud enough, their mic's sounds can still be heard.
In short, your kid shouldn't be playing online video games with adults. If you chose to expose your child to violent content, that is one thing. But all online content is unrated. It cannot be controlled and it will never be ideal for kids and young teens.