Why is 'Macbeth' called a tragedy if the evildoers are destroyed and legitimate powers once more hold control in Scotland?

In the Shakespearean play 'Macbeth', the title character of the same name and his wife were represented as evildoers. They usurped royal power from the legitimate royal line by killing King Duncan I [d. August 14, 1040]. By the end of the play, the future King Malcolm III [d. November 13, 1093] re-established his father's legitimate royal line by getting Macduff to kill Macbeth [d. August 15, 1057]. But the play actually was called 'The Tragedy of Macbeth'. At the beginning, readers and viewers saw Macbeth as a brave, noble fighter in defense of his king and his country. But he had the hero's fatal, tragic flaw. He took pride in doing a good job, and wanted recognition and rewards for his good work. That pride was linked with raging, uncontrollable ambition. That ambition was a trait that he shared with his passionate, scheming wife. His pride also was linked with a weakness in his manipulability by the three witches and especially by Lady Macbeth. The play was called a tragedy, because the main character died. Indeed, Macbeth could be seen as a hero whose fatal, tragic flaw brought destruction and death to himself and many of those around him.