This is very true. I think a lot of this comes down to, no matter the technical expertise of the person, the fact that when you're very young, you lack some life experience and are in a different place with different needs than older professionals. That's not to say it makes them less legitimate or that they should be gone easier upon, but it definitely affects the advice. A 15 year old is thinking about college, a 45 year old is worries more about supporting his family, and those factors very much affect the situation.
This implies that 'not' being a teenager makes you a 'seasoned professional'. What makes you seasoned is experience, a 14 year old can be more experienced in programming than someone who is 50 and just starting out, and is likely able to get more advanced in much less time.
I find the younger ones pick up new ideas faster than some other generations, and can get more 'experience' than I can in a shorter amount of time. This is why I find it hard to want to treat them like kids, they are smart and intelligent, and often faster than me. I have no right to tell them otherwise by playing down to them. The best adults in my life were the ones who treated me as equal and respected me.
No it doesn't. Those were two categories of people you would give very different feedback. You would give a 50 year old beginner advice more like the teenager, probably, but still not the same. For one thing, you'd expect them to be a bit less brash about what they've done, because we rightly expect adults to have a bit more perspective on their place in the world. And in fact, we see lots of posts here saying "I've been programming 6 months, look what I did." And when we do, the tone is usually quite different on their part. They know they have a lot to learn, etc.
In my experience as a teacher, I would say that the most success I've had with teenagers was when I was able to show them that I trusted them to do a good job, and that I acknowledged that they could function on a higher level than a child. That doesn't mean I treated them the same as adults, because they're not. Let me give you an example:
When I was in high school, I was among the best young musicians in my state. I was twice ranked principal in the All State Orchestra, and I ended up going to one of the top music schools in the country. I won awards and scholarships and was praised by all, yada yada.
And yet, when I listen to recordings of myself play from that time, I am struck by two things -- one, that I was amazingly self assured, and two, that I sounded terrible. I couldn't hold a candle to any pro in any orchestra you could name. When you're a teenager, you suck at everything that is worth doing. You also suck at recognizing that fact, and are hormonally hard wired to not be able to examine your weaknesses. There are exceptions to the rule, always, but anyone in any kind of advisory capacity to a young person needs to recognize that and treat them accordingly. The last thing a kid who loves doing something needs is to be shown that they suck. Once they have a bit more skin in the game, the self examination can start.
It's different, though in both cases their being new matters to the feedback you can give.
A 50-year-old just starting out as a developer has already established to themselves that they can survive in the world as an adult; they have a history of successes (and failures, put into perspective over time...) that provide a base to their ego when they're criticized.
A teenager has no context, yet -- no way to assess their own value; a minor success may make them feel like they've conquered the world, but it's fragile. If you tell them it's shit, and they haven't actually done anything worthwhile, they'll may well also accept that completely and be devastated.
I run across teenagers who are surprisingly grounded now & again, but I know I certainly didn't feel like I had solid footing (and could navigate unkind criticism without being seriously hurt) until after I was out of college... and learned I could actually cut it in the real world.
That may be true, but humility is not one of the virtues typically associated with adolescence. When they tell you they're a teenager, they're asking you to go easy on them, and there's nothing wrong with that. That doesn't mean they can't also be proud of what they did.
