There are two levels to this. The nobiity and the King (James I, who himself had written a book on Witchcraft), saw a story of a good man led astray by dark forces into the ultimate crimes of treason and usurpation, then justly destroyed by the rightful King and his loyal nobles.

The ordinary folk saw a different play. Shakespeare never uses the term 'witches'. He calls them 'Weird Sisters'. To the ordinary folk of Saxon blood and language 'weird' meant 'fate' and the Weird Sisters were the Norns of Nordic myth. They present Macbeth with his fate, but do not tell him how it will come about. That decision is his own. The implication is that if he had ignored his wifes' suggestions and continued to serve Duncan, he would eventually have become King anyway. After all, the times were dangerous, and who knows what might have become of Malcolm and Donalbain? Instead he takes the quicker path, and accomplishes his own doom in doing so. No man can escape his fate, like the old tale of the Appointment in Samarra. But how you find and meet it is up to you. In the end, Macbeth faces his with courage and defiance: "Lay on, Macduff! And damned be him that first cries 'Hold, enough!'"