Now, I'll leave it up to you to decide whether that's a good thing or a bad thing. Personally, I think it's a terrible thing. All of those pet peeves, all that noob/jerk talk from earlier, mages who AOE without regard for aggro or strategy, and players who duck out of instances five minutes in because "sry my mom makin dinner"-- I realize not all of these things are the fault of kids playing, but I think that a lot of them are. Let's just say that if Blizzard could charge me $30 a month to play on a server where everyone was somehow guaranteed to be over the age of 18 (I'm 26, for the record), I'd take that deal in a hot second.
Now I know, too, that there are ways around it. I play Horde, mostly. I've found a few good guilds for my characters, places where pretty much everyone playing is more mature and can put together a sentence without using the letter "u" as a pronoun. And I know that not all kids play the game like it's a nonstop loot grab/bragging contest-- I'd imagine there are at least a few 14-year-olds out there who really are interested in working together and relaxing on a run through Scholo instead of worrying about what "epix" will drop or winning the DPS meter. But by and large the experiences I've had grouping with people who turn out to be under 18 have not been, let's just say, my favorite parts of the game.
Unfortunately, there's not really a solution, short of the aforementioned age-specific server that's probably not technically possible anyway (kids would still sneak on-- I would if I was still one). I guess I'll just have to continue to be a geezer, sitting there wistfully trying to understand the deeper mechanics of crowd control and aggro management while the kids in my group fight over what their highest crit has ever been. As Neth jokes in the thread (Neth, if you're reading this, rock on for the Neal Stephenson and HHGTTG love!), someday we'll all have to have our own gaming retirement community. Finally, those little whippersnappers will leave us alone.