That's why they play the game.... I can remember on paper all the years that Texas had the best recruiting class in the country, loaded up with 4 and 5 star recruits, and would lose 3 or 4 games a season. On paper they should have been the national champs but couldn't even win their conference. Sometimes it comes down to being able to coach all that talent. In your case to get a very talented group of musicians to achieve the goals YOU set even though they have different ones. Maybe it comes down to mutual goal setting.

I'm almost 50 and I grow weary of all the "this generation" junk. I know all the stupid stuff I did as a kid. I look back and think of all the things I could have done differently, (sports and music), if I'd have just listened to my coaches/directors but I didn't. Because I was a kid. I could have made state but I didn't. I could have had a couple of career options but I didn't. Yet I ended up in the career of my dreams and changed lives for decades. I didn't end up in the career my parents wanted for me. But I ended up in the career I wanted. Looking back I can think of other careers that might have been equally as fun but that's what retirement is for.
Kids are kids. Not all kids are the 1%ers. Not all kids are lazy and unmotivated.

My own kid could have done some things differently as well but as it turns out, they are right where they are supposed to be and doing amazing things even though they made choices in high school that I might have preferred to go a different direction, (losing interest in certain activities, finding interest in others). Turns out that 3.9 gpa in HS turned into a 4.0 in college and admission to a doctoral program and the activities they chose to do and not do were the right choices. I don't think you can blanket say kids aren't motivated. I can think of a few teachers that would have said that about my kid. And they would have been right and wrong all at the same time. Their subject didn't motivate. Doesn't mean the kid lacked motivation.