As many people have already said, adults like playing with other adults. That being said...
I am a 24 year old single mom with 3 children, and my oldest is 6. I had a 10 year old hit on my NE resto druid (even after i told my age he persisted), made me wonder if parents care more about careers, partners, addictions, etc, than they do about their own children. If my kids could read well, i would not allow them to watch me play, for fear that they may hear (read) the word rape (and many others), and ask about it. I would probably have a pretty bad reaction if i seen any of my children act like some of the kids on WoW (and some of the other MMORPG's out there). TV is even pretty bad for the younger kids to watch, no value to it (example, Spongebob, my 6 year old thinks it is dumb), and they are upping the maturity level of PG it seems.
BUT I seriously think there are some pretty awesome "kid" players out there, and I play with some teens, given maturity level. I am still young enough to relate to teens and have a nice conversation with them. As a parent I play WoW to get some adult interaction, and to kill stuff (pent up aggression, from keeping babies from playing in the {insert dangerous or nasty place here}, arguing with a 6 year old with the basic intelligence of a 10 year old, and the fighting amongst themselves), I am trying to get away from my stress of being a parent, and having the immature kids (and adults) saying stupid crap to me and in chat annoys the crap out of me. Also there are some pretty awesome players out there that you, possibly just me, would think, because of their generation (one of my buddies is 67 years old), wouldn't be with it, that totally blow me away.
When Rome do as the Romans. If you are playing with kids your own age, act your age, if you are playing with adults, don't act like one of the bratty neighbor kids, that we all put up with. But it seems that, for the most part, the kids that are the quiet ones on the servers tend to be pretty awesome.
Adults stress about things that kids couldn't even dream about, time is a major factor for me, I had way too much time as a kid, and not enough time as an adult.
What I might consider doing is asking some one that is asking your age right away if they would consider waiting until the end of your conversation to ask again, or say mid teens. Personally, your age would not matter to me if you act mature (which, it seems you do) and knew how to play your character.