I'm sure the nerds here will find ample opportunities to tear this movie apart, but keep in mind that the "average American" (a) doesn't know much about Snowden, other than "he stole secrets and hid in commie Russia, so he must've been working for them", and (b) just believes what the government says. To counter the powerful voice of the government, you need an equally powerful voice like Hollywood. Maybe this movie…
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.