Oliver Stone likes to destroy characters on the big screen paying attention to the flaws rather than the charisma of his charactes. Jesus, I didn't remember a single battle scene from the movie "Alexander" and this guy went from Greece to India on horse battling his way out. He is considered one of the biggest strategic minds in history. He was the only leader I recall who changed the faith of battles consistently by making swift, unexpected moves with his cavalry hitting the enemy where he least expected it. Being gay[2] is not the reason why Alexander was named "Great".
[1] In the case of Alexander he admitted that it was a huge failure, but I'm not sure if by failure he and I mean the same thing, probably not.
[2] Sexual relationships amongst men were a very natural thing in ancient Greece, especially between soldiers. Indeed Alexander was married twice AFAIK.