In Death of a Salesman, is Willy's statement that spite is the source of Biff's failure correct?

In the final confrontation between Willy and Biff, the two
men argue about the conflicts that exist between them. Biff attempts to lay down his
side of the dispute, not in reconciliation as much as truce. Willy, however, sees this
attempt to end the argument between them as an act of
spite. 

A natural interpretation of Willy's feelings
suggests that Willy is simply hurt by Biff's announcement that he is going to leave and
never come back to his parents' house. He is hurt and feels that Biff is hurting him
intentionally, so he claims that Biff is acting in
spite. 

This is not true from Biff's perspective. Linda has
told Biff to leave. Biff has also realized that he has been carrying around a fantasy
about himself and a grudge about his father for too long. He wants to let go of both and
is willing to say that Willy is not to blame for
either. 

Willy will not accept Biff's truce and refuses to
really hear what Biff is attempting to say.

Spite is not
Biff's motivation, however, and that is clear. His motivation is quite the opposite. He
is motivated by sorrow, penitence, and love (for his mother at least, and maybe his
father too).