There's a reason there's stuff like COPPA (Do most things without an adult on the internet at age 13), and there's a reason you can only drive and work at 16, a reason that once you're 18 you're an adult, and etcetera.
That being said, I am 13 and know people around my age that are extremely mature, maturer than adults would think they are. I guess people want their staff to be 16+ because that's how it goes for most places. You can only work when you're 16+ IRL (unless it's with your family) because you have enough experience in life and have learned and been taught enough to be mature enough to work. That's likely the same or at least similar reason owners of servers want their staff to also be 16+ -- they will handle situations better than most people younger than them (but not all!). Also, MC is extremely popular with people under 16 and even under 13. They're probably also trying to weed out the 9/12 year-olds.
So, that's my opinion. I think if people are under 16, they can show that they're mature and smart and maybe they'll be accepted as staff. I mean, I've seen it happen before, so there's hope for us mature, not-16+-year-olds!
