The rock and roll hall of fame has become less relevant over the years as far as I am concerned. Once they started inducting clear pop and rap while overlooking major rock influential artists it kind of fell into more of a "who can we induct and get ratings" deal than something genuinely about celebrating rock.
That said, Kate Bush absolutely should be in there, and 20 years ago. She is one of the most talented and creative music minds in rock history, and she paved the way for a lot of female singer/songwriters that have come along since.
This whole fan vote business is likely a sham anyway. Doubtful it will have much impact with the music industry execs in charge of the "hall of fame."