It's kind of weird: the HOF determines which "versions" of bands get in. For example, the Ramones got in, but only the Joey-Dee Dee-Johnny-Marky line-up. C.J. is not in the HOF. Stranger yet, *all* of the Grateful Dead's line-ups, including Vince Welnick, are in. Go figure. I have to imagine Hagar would be part of the induction - he was frontman for at least as long as Roth, and they had lots of commercial success with him.
I tried really, really hard to like that new VH version but I just couldn't. They lost me with him.
Sammy Hagar is not a member of Van Halen. He was just a hired singer.
Stranger yet on that Ramones lineup is that the original drummer, Tommy, who played on the first 3 albums was not inducted.