Why is che guevara regarded as a hero?

both he and fidel castro were responsible for many deaths and jailing of innocent people for the so-called "social revolution" The thing that really bugs me is that his imagge is plastered all over the place. posters,coffee mugs, t-shirts. The majority of' people have these images and don't have a clue who the man was or what he stood for. They may has well have a picture of hitler on their shirt. I can understand if its in cuba but this is the usa.