The film is an adaptation of a graphic novel which itself takes grand liberties.
"300" has never, as part of its promotion, claimed "Based on a true story" or "Based on actual events". This ain't the History Channel.
Geez, lighten up, already. It's just a movie.
I'm not saying that the movie had to or even should have been 100% historically accurate.
But on paper, on film, or in history, while you may root for the Spartans because you want them to beat the Persians, you can't call them good guys.
Regardless of historical accuracy, anytime the Chronicle renders a poor rating to a movie, it's usually due to its self-loathing anything American and its "socially enlighted" anti-success viepoint. I will find worth watching those movies an enjoyable experience! Otherwise, the Chronicle will heap loads of praise on movies with perverted themes.
Thank goodness for that. 'The Hitler Channel' seems fixated on Nazis marching into Poland, and all sorts of flying war machines Hitler didn't have, but wanted. The fall of a good network!
But it IS based on a true story.