I imagine this is because everyone has traits similar to ADHD. Not wanting to do your homework isn't a unique feeling, but if you can literally never force yourself to do it even with serious personal consequences, you might need medication.

Diagnosis is based on severity, and in reaction to the hideous over diagnosis of ADHD in particularly very young boys at the start of the 2000s, its become very difficult for even those people with bad, medication-indicated ADHD to get diagnosed. Everyone loses and it just sucks.