I think several factors play into this behavior.
They don't make that much money.
They are still young enough to be unaware.
They grew up with iTunes.
They don't understand the real meaning of "connection."
I read a Seth Godin interview where he said the only thing of value that a musician has left to sell is intimacy. I thought that was a dumb statement the first time I read it, and after many gigs watching the Y factor walk past the tip jar, I still think Godin's full of shit.
I live on the cusp of Boomer and X. My parents were continually exposed to live music. In fact, it's my parent's generation that tip generously. They love the presence, the "connection" and the idea that someone can add value to the atmosphere with a voice and a guitar.
The Difference Between X and Y
My generation, which is more X than boom, went out to connect with friends. We went to concerts. That's how I spent my after school job money. I was also raised on old fashioned manners. You demonstrate your appreciation for something good. You tip to keep the good stuff coming.
Here's the problem, Generation Y probably doesn't care if there's a real human being producing the music. After all, they spend more time staring at their smart phones than listening to my music or even talking to a date. The date doesn't seem to mind because that's just the way they are. I get seriously sad and lonely just thinking about the future.
So what do we do? Priming the tip jar will get the older people to give a few bucks. It won't work on the youngsters. Should I start a facebook campaign? Tweet it? "Tip you brats." or "#tipyoubrats.
If you're huffing and puffing because I stepped on your toes, then I've been effective. I read somewhere that this generation lives with their parents longer, has better family connections, and desires meaningful relationships. I think the misstep comes from trying to find that connection via an electronic device. It will never be satisfying.
What Can Musicians Do About It?
I want my musician friends to work on their social message. Make sure you promote the real meaning of "connection." Then make a habit of talking to those young people. I admit to being really bad about sinking inward when I'm doing a dinner type gig. My generation and older will engage with me, and I always love it, but this group of people who claim they need connection can't do it in the flesh.
I think the work is up to us musicians. Maybe make a sign that says, "If you tip, I will talk to you, and smile at you, and like you." Gen Y loves music. No doubt. It's just a matter of honing the soft skills to make them understand real connection.
Gen Y musicians can learn from this, too. Don't just play your gig and scoot. Take a little time to mingle. Here's a scary suggestion. Turn off your phone. Once upon a time, the phone was connected to the wall by a curly cord. That's why we old folks are so damn good at small talk. Turn that SOB OFF! You're an entertainer, and part of being a good one is learning how to really connect.