Musta been luv. This will really get me into trouble, but I never thought he was much of a singer either.
The Beatles had two good musicians Ringo {a great drummer not singer} and George Harrison who could both sing and definitely out play anyone in that band. Lennon and McCartney were good song writers though but IMO hearing his later works George is what really made The Beatles sound as far as the music goes.
A lot of bands best players didn't sing much. Like Don Felder formerly of The Eagles. One fantastic guitar player but did not sing. He also carried most of the actual playing when Walsh sang. Walsh, Schmidt {the Bass player} and Felder were the later years talent in that band. From what I understand Frey and Henley fired Felder a few years back.