Why cant Biff tell his father what happened with Bill Oliver?

The
problem Biff has with trying to tell his
father what happened when he went to see Bill Oliver is
symptomatic of the
problems Biff has been having communicating with Willy for much of his life.

Willy is a good talker but not a good listener. He has an unrealistic picture of his son
Biff
and consequently has unrealistic expectations of him. Willy wants Biff
to be a highly successful
businessman to make up for Willy's own inadequacy.
Biff has tried to please his father because
he loves him and wants his
approval. But Biff is finding it harder and harder to go against his
own real
character. The meeting with Bill Oliver, such as it was, brought Biff's inner
conflict
to a head. Even though he cannot get through to his father at the
restaurant, Biff will
eventually force him to listen. Even so, Willy will not
agree with Biff's self-assessment or
with his son''s assessment of him. Biff
says a lot when he says:

I am not a
leader of men, Willy, and neither are you. You were never anything but a

hard-working drummer who landed in the ash can like all the rest of
them.

It is almost comical when,
earlier during this climactic showdown
between father and son, Willy
says:

I am not a dime a
dozen! I am
Willy Loman, and you are Biff Loman!

Ironically, this statement makes them both seem all the more what they truly
are--a
couple of nobodies, a pair of losers.