ants and stinkbugs
It's likely that Macbeth would not have killed Duncan if the witches had not planted the idea of his kingship in his mind. While Macbeth struggled with ambition, the witches' prophecy ignited and intensified his desires, leading him to take action. Without the witches, it's possible that Macbeth's fate would have unfolded differently.
Normally, people would not blame the witches. They just said things and Macbeth reacted by doing things. The witches can only be held to blame if you think that Macbeth had no choice in his actions. But if he had no choice, how come the witches do have a choice?
MacBeth meets the three witches with lady MacBeth
The witches in Macbeth do not have individual names. They are only referred to as the three witches or the Weird Sisters.
Macbeth.
The witches had predicted that Banquo's descendants would become kings whereas Macbeth's would not. Macbeth resented that. Also, Banquo was aware of what the witches had said and might suspect Macbeth of Duncan's murder. Macbeth says, "My fears in Banquo stick deep."
The witches only gave Macbeth prophecies. It was his decision to do so after Lady Macbeth persuaded him. Although the witches' intentions was probably to cause this murder, the witches did not make Macbeth muder Duncan.
Macbeth did not like what the witches had told him.
The witches
Macbeth does.
No, the witches are proclaiming and predicting that Macbeth will be king and they are praising Macbeth.
Lady Macbeth echoes the words of the witches when she says "All hail, Macbeth, that shalt be king hereafter!". This echoes the witches' prophecy that Macbeth will become king.