In Act II of Pygmalion, when Doolittle says, "I'm undeserving, & I mean to go on being undeserving," why does he not want to better himself?

In Pygmalion, Alfred Doolittle is
Eliza's father.  With the character and values that truly mirror his compound name
containing the words "Do" and "Little," it is no surprise that Doolittle boasts with
this statement.  Let's look at a little bit more what he says in Act II with a certain
"gift of rhetoric" that eventually gets him in
trouble:

I ask
you, what am I? I'm one of the undeserving poor: that's what I am. Think of what that
means to a man. It means that he's up agen middle class morality all the time. ... I
don't need less than a deserving man: I need more. I don't eat less hearty than him; and
I drink a lot more.

Considering he
finds himself "undeserving, and I mean to go on being undeserving," even his daughter
Eliza (of the same metal as her dad, of course) is absolutely
disgusted.

You see, Eliza is, in fact,
trying to better herself.

Alfred Doolittle considers
himself as one of the "undeserving poor."  Why?  Because he does not do any work,
doesn't want to do any work, and never plans
to do any work, no matter what.  Oh, there's a wonderful song in My
Fair Lady (the musical version of Pygmalion) that deals
in this very issue:  "With A Little Bit of Luck." How's this as the answer to your
question:

The
Lord above gave man an arm of iron
So he could do his job and never shirk.

The Lord gave man an arm of iron-but
With a little bit of luck,
With a little bit of luck,
Someone else'll do the blinkin'
work!

Sums Afred up quite
nicely, eh?  Not sure if Shaw could have said it better
himself.

Back to the point, though.  Why doesn't Alfred
Doolittle want to "better himself"?  Simple!  Alfred Doolittle is perfectly happy the
way he is living and has no desire to change it.  Ah, but that's about to change thanks
to Professor Higgins.  : )