That is not very since impressive since half of those bands only have one or no great albums (unless we are counting live, which I don’t unless (x2) you want to count compilations).
I think objective greatness is not really the most important when it comes to RRHOF’s induction qualifications (Which I want to emphasize are DUMB. Influence (in the critical community IE their voters and base’s eye) is #1, influence in music as a whole is probably #2, and I’d say greatness is #3 with popularity at a very distant fourth.