This is SO true. For example, almost no guitar player correctly plays the descending pentatonic lick that starts on the high E in Back in Black. Almost everyone plays it straight when it actually has a swing to it - it's tricky as heck to play right. I've seen AC/DC tribute bands that don't get this right. Same with the bass and drums - those guys have a way of playing seemingly simple things that have a killer pump and groove that is often overlooked because it's not as difficult as Dream Theater.
Same thing with playing Stones tunes - I hear drummers, guitar players, etc. talk smack about how simple the Stones stuff is to play. Sure, it's just a handful of simple chords. And then you hear the smack talkers try and play a Stones tune. They don't get the rhythmic push/pull thing that Keith and Charlie do so well. They usually completely lack swagger. And I can't tell you how many times I've witnessed guitarists playing a G5 power chord in Honky Tonk Woman - that's just offensive
Just because it isn't difficult on a virtuoso notes-per-second scale, doesn't mean that anyone can play it right. In a recent Ernie Ball video, Steve Vai had some great points about trying to play like guys like Kurt Cobain, Billie Joe Armstrong, etc. - in a nutshell he said "it's not so easy".
