Cardio is great for cardiovascular conditioning.
Its not "needed" to get shredded, but does help if one isnt restricting calories too much.
We all know some of the HIT / Arthur Jones type bodybuilders, who are ripped (and can get so for a contest) who are anti-cardio.
(Well, I know a bunch at least).
I think everyone is right here, it burns calories, it gets you in shape, but definitely not
"needed" if one wants to get ripped.
(Tuna, water, salad) gets these people shredded. (And gear).

Their heart-health may not be so good though.