He's equating the 300 with an historical documentary when it is a work of fiction.
No he is not. He is criticizing it for being a historically inaccurate work of fiction that selectively uses its inaccuracies in order to advocate a philosophy that is anti-democratic.
The man is being delusional. Noone should equate or confuse a work of fiction with reality and real history.
The violence didn't bother him at all though.