He's not mad at Barca, he loves Barca. (and he'll always will)
He's mad at the people who asked him to leave, weeks after he scored a goal in the CL final and made maybe the best season in his career. I don't take his words as talking against the club, I take them as talking against some people in the club. Even if it's the same thing for someone, it's not for me.
As a FCB fan, I don't feel personally attacked by Samuel Eto'o, because I know that he doesn't mean that. He doesn't mean to target Barca, the fans, the team or Catalunya. I'm sure about that and I don't see nothing wrong or abusive, because of which I should feel something negavite about him.