This is no way disregards the difficulty of living with an actually severe case of ADHD but is not what most of these people are dealing with.
EDIT: many seem to have misunderstood what I mean by this. I'm not saying these people are only claiming to have ADHD to use it as an excuse. What I mean, is that they may very well do have, and they're using it as an excuse. Mostly to themselves.
I likely have some combination of autism / ADHD myself as I relate hard with much of the posts / memes I see here but I also realize that I don't need pats on my head about how I shouldn't feel bad about my struggles because it's "all due to ADHD". Yeah, maybe I'm playing life on a hard mode but I still want to play.