As a parent of a child with ADHD, bad grades are a signal they aren't able to cope or excel in their normal state. If the child is able to get good grades then it's really hard to justify putting your kids on a mood altering drug.
My oldest child has ADHD and is currently on drugs for him to be more successful. He started taking ADHD drugs in high school and that made it much easier as a parent to make the decision to put him on the drugs because he could provide intelligent opinion and feedback.
I know there is a tendency here to think that the parents are doing this for nefarious purposes, but wouldn't it be more nefarious to put your kid on mood altering drugs because they were hard to deal with?
Everything is a shade of gray for most kids. If it were black and white it would be easy. I want what is best for my kid, but that's not necessarily an easy thing to know what is best. If it's a close call, then it seems the safest route is the one where you don't give your kid potentially addictive mood altering drugs... and that's where we were for several years in junior high after he was diagnosed. He actually did quite well during covid doing school at home, and when he went back he struggled.
Let me emphasize again, this is not an easy decision. Almost all parents are trying to make the best decision for the sake of their child. You can always come up with the shit parent examples, but for every one of those there should be at least two or three good ones trying to make the best decisions possible.