I guess I'll always be a bit of a hack on bass. I can kinda strum through playing rhythm guitar and sorta sing along. Truth is, I'm a very good and practiced vocalist (I have a very good paying gig every weekend...that's 100% acapella no less). But for some reason I'm just not there yet when I'm playing my instrument of choice.
As a few others have mentioned, and all others have shamefully left out, Gene Simmons has been doing it on the biggest stage of them all, all over the world, and being paid for it better than ANYONE in the history of music. Let that sink in. Gene Simmons is FAR and away the highest earning bass player, period, end of story. And, if you search a bit, you'll find a talented musician under all the crap.
Also, Paul Gregg of the C&W band "Restless Heart" is a great example of a guy with an amazing voice and great chops.
Hmmm... has he made as much money as Paul McCartney?