Like, no seriously, the state department classified him as a terrorist until like 10 years before he died. He was already a beloved figure In his modern incarnation as we remember him now way, Way way before The US federal government ever accepted that he had actually just won and was not a terrorist anymore, but a statesman.
Freedom fighter/terrorist dichotomy aside, he definitely used terror to achieve political goals. We look upon him kindly because his cause seems just to us, and because he won.
Choosing peace instead of genocide when he had his hand on the button helped as well