He may very well have been a perfectly lovely man. I tend to assume that 99% of the population is composed of perfectly lovely people that though they may disagree on the means, have ends that include improving the lives of people at large.
Che Guevara is not one of those people. People that say things like this, are removed from my list of generally OK folks:
"To send men to the firing squad, judicial proof is unnecessary. These procedures are an archaic bourgeois detail. This is a revolution! And a revolutionary must become a cold killing machine motivated by pure hate."
Next time you see someone in a Che shirt, kick him in the shins.