normally the X doesn't do Y (bad thing) argument is being made to push the cause of getting more X out there, or at least keeping the supply of X from getting limited.
Is there a movement to increase dopamine access in middle America I'm unaware of?
He's arguing that colloquial demonization of dopamine as the cause of addiction isn't fair because dopamine is necessary for normal cognitive functioning and isn't accurate because dopamine is not itself the feel-good hormone, then proceeds to tell that dopamine helps attribute reward to behaviour.