Well, if you use one song to make up your mind, Led Zeppelin isn't rock and roll. Either way, I am sure you have already condemned Led Zep to hell for all their fornicating and what not.
Clemenza condemns "f--kin' Led Balloon" not for fornication, but for the unpardonable sin of musical masteurbation. Emerson Lake & Palmer, Yes, Genesis and other Brit rockers of the early-mid 70s were also guilty.