ADHD is ultimately a disability of reduced executive function, and all of the seemingly disconnected symptoms are connected by that common fact. Everyone has challenges with executive function in life - especially if chronically sleep deprived, but the degree of severity varies substantially to the point where people with ADHD are radically different from people without on a lot of axes.

It's quite the opposite of "absolve[ing] people of the responsibility to work on their concentration." Instead the diagnosis shows that this is indeed the reason why people with ADHD have been struggling to meet expectation their whole life, and there are specific actionable things they can do to fix it, that aren't the same thing that work for people without ADHD.

I had a huge amount of guilt and shame that comes from having tried every productivity, organization, and concentration technique to no avail. I felt like I was pushing against an invisible brick wall that nobody else had. I could deeply care about something, focus all of my energy on it, and yet fail to do it for reasons that remained a mystery to me- when peers with less innate ability and less motivation/drive still did it easily. The diagnosis made sense of this, and pointed me to solutions that actually work.

As a parent of a young child with ADHD that was kicked out of 5 schools before getting a diagnosis that led to him thriving... the idea that it is just an excuse to avoid personal responsibility seems absurd. I could (and have) guilted myself into thinking this way about myself, but can't really apply that to an innocent young kid trying their hardest to fit in, and constantly being rejected and abused by adults and peers due to their brain just working so differently.