Well, yes - the Persians were definitely the 'baddies' in that movie. No one wants their country to be the baddies in a movie, whether it is 300, or Mel Gibson's 'Patriot'. In both movies, there is a naive polarisation of history, and a lack of acknowledgement (in the first instance) that many Greeks fought willingly in the Persian army, and that (in the second) 'American' families of several generations standing fought for the Brits, and that Englishmen resident in America for only a few years fought with the Americans.
But, as Horatius says, the Iranians are not the only ones who destroy their history for short - term gain. We Brits happily plough new roads through vulnerable archaeology on a daily basis so we can continue to drive everywhere in this tiny congested island of ours. The Iranians are doing this to produce electricity and irrigation. We do this so wealthy commuters can knock 30 minutes off their driving time to work, whilst living north of London, where larger houses are cheaper. Who are the greater Phillistines?