Second, don't listen to them and don't water things down. And don't teach them note by note. Small chunks, sure, but stop teaching note by note and demonstrating on every instrument. They are learning by rote. Make it their responsibilities. How big is the program? if you have 40 plus woodwinds I assume you have at least two concert ensembles. Make marching nice and simple. Easy drill, functional music and move on. Start to introduce stand tunes one at a time. Find a hook that really gets them excited. Maybe even let the kids pick the stand tunes. I had a rule that said it had to be in print but they could bring me a list of tunes each year. Staff picked some and the students got to pick 5 or so new tunes (or old tunes out of the library) every year. That meant we were playing what THEY wanted. They stopped trashing music when it was their friend that picked it.
For Concert, have one small group that cares and one large group that is working daily on getting better. Don't tell them they are the dumping ground though.
Out stubborn them all. Just keep working daily and maybe have some passoffs. But not for a grade because the kids will accept their F and then you lost. Make a few scales a test but tell them they will retest until they pass because it isn't about the grade but the skill. Every grading cycle maybe you have 4 scales total. This gets you your SR scales by December at a minimum. And they don't get to retest in class. That gives them the floor to be silly. The retest will happen on THEIR time. I also liked to do a thing where I would have the student "pick" who they were giving their grade to before they tested. They called on their friend. looked them in the eye, then played their scale. The friend got their grade. And I did that all the way around the room. The kids thought I was kidding the first time I did it. But their peers didn't find it so funny when they were getting the crap grade for a scale. And the kids after a few times really got tired of being the bad guy when they knew their lack of practice was going to personally cost someone else a grade. And before all the lawyers jump on here, I didn't care when a kid told me I couldn't do it. We had the short conversation of how UIL performances were often negatively impacted by the person that didn't know the music, not the students that did and this was simply working towards leveling the ensemble and teaching accountability. And I had that conversation with a few parents as well but not very often and I NEVER changed it. And in reality, we had 30 grades per grading cycle so it never really affected their grade anyway. It was more about affecting their attitude and approach and peer pressure is a wonderful thing when applied correctly.
Today you have 6. Tomorrow you get that 7th and eventually more want to be good than bad and you are on the downward slope.