It is a difficult task to claim that Macbeth is not the tragic hero as most see the influence of the witches and how Lady Macbeth manipulates him until Macbeth's "vaulting ambition" takes over completely. But, all is not what it may seem as "foul is fair" and "fair is foul" even by Macbeth's own admission of the day as "so foul and fair a day i have not seen." (I.iii)
There are many reasons why Macbeth should be held accountable. Macbeth is considered to be a tragedy and the "hero" always somehow redeems himself by the end of the play in a tragedy. Macbeth does not redeem himself - except to strive on to the end fully aware of his pending doom. Unlike other tragedies, Macbeth concludes in spite of him not because of him and
all is well through the forces of good that ultimately correct all the evil Macbeth has unleashed.
The involvement of the witches is made much of but it is important to note that they are not capable of exerting any evil themselves and they do not actually
signify the actual existence of evil but suggest instead the potential for evil in the world.
People are faced with choices every day and Macbeth should have chosen more wisely. The prophesies appear to come true almost simultaneoulsly with the promise of the Thane of Cawdor. Macbeth does wonder whether the witches are "good" or "ill." Does he not recognize the coincidence with his recent military achievements? Banquo is not surprised by the witches claims as he wonders "why do you start and seem to fear.."(I.iii) thereby supporting the theory that Macbeth would have received such an honor anyway - no supernatural elements necessary.
Duncan says "signs of nobleness...shall shine on all deservers" (I.iv) as he addresses Macbeth, his "cousin" and Banquo in thanks for their conquests. Later, as Macbeth struggles with his conscience and whether he should commit this heinous deed or not, he points out himself that Duncan is his relative and has recently "honor'd me of late"and is therefore more deserving of his allegiance:
We will proceed no further in this business (I.vii)
but he is quickly swayed by Lady Macbeth and in his efforts to "do all that may become a man"(I.vii), it does not take him long to put on his "false face."
Macbeth allienates himself from others and even Lady Macbeth, his greatest fan, in thinking that he is invincible and "perfect", and his efforts to prove his manliness
first by murdering Duncan, then Banquo, and finally Macduff's family
just render him less humane and if he is less humane then he is not worthy of his audience's sympathy.
Macbeth interprets, is confused but excited and fascinated by the prophesies but does not need to force the progression of his rise to power through evil means. A man so influenced by their supernatural powers should surely have waited for matters to fall in to place. Macbeth's ambition, of which he is fully aware, should be manageable.
Further to the argument that Macbeth does not deserve sympathy is the fact that Lady Macbeth becomes more haunted as time goes by and she cannot remove that "damned spot. " If she really has the influence on Macbeth that some claim, he would not have been able to forge ahead with his murderous deeds. This is however what you would expect of a psychopath
who lacked any moral integrity
and the foresight to recognize his own destruction.