How does Macbeth gain the sympathy of the audience when he recongnizes his tragic flaw??

Answer 1

What makes you think he gains symphaty?

Answer 2

Once Macduff tells Macbeth that he (Macduff) was NOT "born of woman" (because he was a Cesearean-section birth), Macbeth knows that he's absolutely hosed. The witches' prophecies have all come to pass, and, clearly, Macduff is the man who was born to slay Macbeth.

But, even in the face of this fact, Macbeth refuses to surrender. Instead, he falls back one last time on his courage, and the greatness of his skill at arms. Even though he knows he's opposing forces far greater than his own, he challenges Macduff, and decides to go down fighting, rather then endure the shame of surrender and capture.

I wouldn't say that he necessarily gains the "sympathy" of the audience by doing this -- he's been responsible for too many horrible murders for that to happen -- but I think he redeems himself ever so slightly by making this one last HONORABLE decision at the end of the play.