Canseco is an interesting person to judge. In real life, I'm sure he's an obnoxious douchebag you can't stand. But from a public perception, he's made such outrageous claims and been slandered for them, then proven right, and taken such a strong stand, that you have to have some respect for him. Also, seeing him on The Surreal Life, he's not so obnoxious as to not mind poking fun at himself. I think he's just arrogant and violent, a macho man, but you have to understand how from a celebrity, public media perception, some people have a positive view of him, particularly considering the cost and ridicule he faced with his book and coming out with the truth about steroids.
Not a defense of him, I agree, I couldn't stand him if I met him. But I understand totally how some have a positive view of him, because he does have a few very strong positives in addition to very area negatives.