It's not a narrative. It's just common human decency. WHY THE MALICE? They made a bad decision - great: you get to feel superior.
... Are you done yet? Cause that person didn't just disappear after you got done feeling all high and mighty. As someone who has know quite a few theatre, dance and other such "dumb majors". I actually know quite a few who've become very successful working in their field. They may not be actresses or professional dancers, but they work close enough to the field that they feel their degree is useful. Many also chose to work outside that field in other decently paying jobs (technical writers, editors, etc).
Why do you feel the need to just act as if it's hopeless and throw these students out? Is your need to feel superior that significant?
You can make the argument "well most actors never make it as a broadway actor". While true, do most software developers make it as a Google developer? And how likely is it that someone whose talent lies in acting is also talented enough to do well at software development? Sometimes, you should play to your strengths, even if the relative bargaining power of your strengths are not as strong as someone else's strengths. That doesn't mean you're not following the best path to "have a better life".
[0] http://www.actorsequity.org/agreements/agreements.asp?code=0...
Sure, not everyone works at Google, but the people who don't can still land jobs at a million different companies for a living salary. An actor who's not landing roles is working a survival job (waiter, barista, etc) so they can afford to spend time auditioning. And remember we're talking about somebody on the verge of homelessness -- they're going to have to compete with actors from wealthy families who paid for their rent and a degree from Juilliard.
At 17 people will try to do what they are best at and play to their strengths. That’s really reasonable at 17.