It's a bit hurtful that they would say "teenage laziness," when it could be depression. It started when I was 12 (probably). I slowly started losing interest in doing things that I enjoyed, even more so about the things I didn't enjoy doing. By the time I was 15 I stopped caring about my future and from a straight A student I became a C/D student. When I started high school that I wanted (we have similar requirements…
"Lazy" is also what kids with ADHD are labelled. I think "lazy" is a cop-out explanation, since it doesn't actually explain anything. Often the incentives are aligned so that it's in the kid's best interest to put some effort into homework. If they're not doing it, treat it like a debugging program: why aren't they responding to the incentives? Could be depression, ADHD, perfectionism/fear of failure, or a bunch of o…
However I do agree with you that we shouldn't be branding kids as "lazy" without investigation first.