It might be more precise to say that this is a “spoonie” song. If it is “about” anything, its about feeling sick, weak, and depressed all the time, experiences we know were familiar to Kurt Cobain. It’s not an uplifting or even particularly empowering song, unless we can agree that recognition and commiseration can be empowering. I certainly think they are, in limited doses. Plus, even the most optimistic and functional among us with disabilities can relate once in awhile to the feelings expressed here, both by the lyrics and by Cobain’s classic “Unplugged” performance.
P.S.: It's great seeing Dave Grohl looking so young and fresh-faced! I mean, it's not like he's an old man or anything now, but here he's really such a kid. Seeing him in this video also underscores how his basically sunny disposition both contrasted and mixed perfectly with Cobain's dour personality.