The person blaming his parents because they tried to do their job of, well, parenting a child with ADHD. I’ve read that psychotherapy is much more difficult when there is no-one to blame. So it might help for him, until he will have his own kids with ADHD and fail in a completely opposite way. I would not recommend anyone to blame parents of neurodivergent kids, as it is a very difficult job to do right.
I have been diagnosed both autistic and adhd and I experienced food insecurity despite living in a house with several balconies and a detached garage bigger than my friends' families' houses because my parents thought I would get over it and start going out to eat with them if they didn't bring me any food. I don't think they intended deliberately to harm me - or realize that me not going out to eat with them didn't mean there was enough food - but their authoritarian way of thinking did the harm nonetheless and it's a completely predictable outcome of such a way of thinking; so it's not "I didn't mean it" so much as "I don't want to think differently because I value my attachment to this mode of thinking more than the wellbeing of others; and when I harm them I'll say 'nothing could be done' because changing how I approach the problem isn't on the table".
The healthiest thing most autistic/adhd people ever do is moving from 'I am sick' to 'the society I inhabit has an autoimmune disorder'.