In Arthur Miller's Death of a Salesman, I believe that Biff is trying to make his father see Biff—and life in general, perhaps—more clearly and more accurately. Willy does not live in the present, but in the past. And a great deal of that time is spent in discussion with Willy's dead brother, Ben, while Willy has imaginary discussions with his successful and much-admired sibling.
Willy always acts like Biff is just getting out of high school when his options were endless…until he failed his math final, failed to graduate, and lost his football scholarship. Willy ignores this and talks all the time about how great Biff is and how he is really going places in the world. Biff's anger stems from the fact that Biff is forever trying to address the issue, and Willy is always brushing it aside. Biff finally confronts his father with hard words:
You were never anything but a hard-working drummer who landed in the ash can like all the rest of them! ... I'm nothing, Pop. Can't you understand that? There's no spite in it any more. I'm just what I am, that's all.
Willy's refusal to see Biff as he really is makes Biff feel worse than he already does about his inability to be a success in life, and if Willy would accept Biff for who his son really is, then Biff might be able to move on and make something of himself.