Alexander assassinated rivals a dozen at a time, slaughtered innocents by the thousands, and exterminated entire tribes of people. It's no exaggeration to say that Alexander killed off a generation of Macedonian officers—veterans he needed to run the army he inherited from his father, Philip.
He even killed his step-mother and whilst sleeping with a whore in a drunken stupor, ordered for mass destruction of Percipolis, the Capital of Archaemenid Persia (Darius I). No doubt the Persians (and Zoroastrians) refer to him as Alexander the Cruel ... far from the 'Alexander the Great' reference he accidentally and unknowingly enjoys in the world.
Some historians say that whilst he had a premonition that he would die early, he therefore wanted to leave his mark on the sands of time by building and consolidating a large empire by his destructive cruelty hoping that would immortalize him.
Men of mindless pursuit work to build their glory wishing to be remembered and recognized by future generations of people who may know little of him and the cruelty he unleashed on men of his time to build his glory.