Right, because ending up a great musician instead of a great watcher of television would have been awful.
He could have replaced guitar with model airplane building, riding bikes, making friendship bracelets, or training a giraffe.
The point is, good time management makes time for the things you need to make time for - and in this person's case, TV happened to be his vice.
I can't think of a potential upside that you expose yourself to by watching TV (other than the immediate gratification), but maybe there is something.
I hate the "agree" posts, but since no one else can see how upvoted I can only dream you've been, I decided this comment was worth the -4.