Quite frankly: I never considered the Cure a "rock'n'roll band" - there are only a few songs which might be described as "rock" or "alternative rock" or whatever...
Additionally I do consider this whole "Rock & Roll Hall of Fame" a bit of a joke. (When you look at which bands were in and which were not at some points in time!)
I'm pretty sure: on the one hand Robert would be pleased if they'd "get in", but on the other hand he doesn't really care about such things, as this is more about "the music business" than anything else...