Billy Idol made "Mony Mony" bigger than Tommy James & the Shondells..... at least I think so...... Does that make Billy Idol less of an artist?
I don't think so... but he also had plenty of his own -- and his BEST songs were probably with Generation X, a band no one's heard of...! But that doesn't mean he's unoriginal -- it just (usually) means they simply 1) like the song, and/OR 2) think they can make some money off it..... good for them, IMHO!