Don't laugh. NEVER laugh. You'd be bitching if they were out in the streets in gangs, stealing your stuff, vandalizing your property, or any of that other shit old people complain about. Instead, you have a youth who has a desire to learn and invent something which will hopefully lead them into being a productive member of society instead of serving 20 to life for cooking meth. Young folks, especially in the high school age range, are easily discouraged and you ridiculing them about being too hipster or whatever will only alienate them. When faced with this situation, I will show them how to blink that LED with their Arduino, then show them how to blink it over a USB port with their gaming rig, then show them how to blink it with a mechanical cam switch (old points distributors work great for that fyi). If I've got some lying around, I'll show them how to blink it with some vacuum tubes! What you have to do is find out why they chose to do it the way the are doing it (typically because that's all they know) and then show them all the choices available, why you'd use each one in a different application, and show them why they get to use that Arduino now instead of wire wrapping an 1802 on perfboard. The key to all of this, I've found, is maintaining the balance between lengthy enough to get the concept across but short enough to keep them from picking up their phone and tweeting their facepage.
Besides, grandpa, you should be
happy the hipster Makers are doing what they do. Thanks to steampunk, vacuum tubes(especially nixies) are making a huge come back. I have a USB vacuum tube audio amp similar to
this. You couldn't buy that shit when we were kids. You had that 100lb behemoth amp that made the house lights dim when the bass hit, and kept your room 80deg during the coldest of winters. And that was if you had a good bit of money. If you had a little money you might be able to buy a Heathkit. Otherwise, like me, you cobbled together some barely functional and noisy bullshit from an old guitar amp and a half working tube powered CB radio. Now you can get something handheld portable for a hundred bucks with the further satisfaction that your "dying" craft is actually living on and they'll need people like you to teach the new gen.
The overall point is, no matter how they get to the destination, what really matters is that they're taking the journey. Time itself will teach them when they need to blink that LED with an RPi or if they need to use a couple transistors.
/. is always posting stories about how we need more STEM graduates, more hardware hackers, and more programmers. A lot of folks here agree with that sentiment and perhaps you've said as much in the past, so please, don't ever laugh at them. They're sensitive.
DISCLAIMER: I am dense at times. If "laugh at" was just a figure of speech, please don't take the post personally- perhaps someone else can be inspired.