Because to the British they “WERE TRAITORS”. You have to remember that at the time ,those we call “Patriots” were British citizens. They were rebelling against the lawful government. When you rebel against a lawful government ,you are considered a traitor. So , it’s simple, to those who supported the rebellion ,they were patriots. To those they rebelled against,they were traitors. To the British, those who remained loyal to the Crown were considered patriots. You don’t need to be a rocket scientist to figure out and understand this. If we had lost the Revolution, those we consider patriots,(Washington, Hamilton, Jefferson,Franklin,etc.) would have been hung as traitors,and rightly so. Now don’t get me wrong,as an American I revere Washington,Franklin etc. But depending on who looks at them they’re either traitors or patriots.