I say it is beating a dead horse because I think arguments about its composition have been made almost since the earliest classes. There have been blues, soul, R&B and pop artists among the inductees from the beginning, though in the early cases their influence on rock and roll was sufficient to justify their induction except to perhaps some purists. As time went on, and inductees went beyond 1950s and 1960s artists, you also had inductees from other genres, though again you could make an argument for their influence on rock music. The 1997 class included P-Funk, the Jackson 5 and the Bee-Gees, and from then on it was more or less a pop music hall of fame. Then you had people arguing that rock and roll wasn't a musical genre, however broadly defined, but a lifestyle.
I personally grew up under multiple musical influences. My first album was Beethoven's Sixth Symphony. My first real concert was David Allan Coe. My youth was really more pop, disco, country and classical than rock. The early to mid-1980s were as filled with New Wave and hair metal for me as for most casual music fans of the earliest MTV generation. I think like many people I developed more refined musical tastes in my 20s, especially at college, though I tried to avoid the purist snobbism after some early encounters with the "I liked X before they sold out"-type of so-called fan. So the 1980s included more blues, classic rock, hard rock and metal, reggae and hip-hop. I was also an early proponent of so-called "world music", helping to organize playlists for a nightclub in my hometown which included among others one of this years' nominees, Fela Anikulapo Kuti. These days I listen to almost anything from baroque to Neue Deutsche Härte*, though I have a particular appreciation for works which cross and combine genres. The cross-genre works sometimes come across as novelties, but even that's not a big issue (said the guy who had Walter Murphy's "A Fifth of Beethoven" on 45).
Again, I don't have anything against this year's slate of nominees as performers, and I am familiar with the work of all of them except Mary J. Blige, whom I've only heard in passing. I just think describing that as a list of rock and roll performers stretches the term beyond recognition. My age might play a role in that what constitutes rock and roll or rock music was pretty much defined when I was young. I suppose someone who grew up with 1950s Rockabilly wouldn't have a clue what to make of late 1990s Nu Metal.
* "Neue" Deutsche Härte (New German Hardness) probably should be renamed as a genre. Rammstein's Sehnsucht, their second and most influential album, came out in 1997. That's practically classic rock by now.
