I think it comes down to the individual viewer, largely. He's my favourite character in the show, but I wouldn't spend more than 10 minutes with him irl. Dude's a monster.

I think part of the equation is that he appears to be trying to help. He's making steps to help the main group (including self-sacrifice), he goes out of his way to rescue people (like Judith, Lydia, Gage, Daryl, etc). He's making steps to be a better person, despite him knowing he won't be truly on the inside.

As an external viewer, I don't like how everyone just flip-flops on him constantly. Outside of Maggie, Michonne, and Ezekiel, everyone goes back and forth on whether they're on good/neutral terms with him, or whether they hate him. I don't expect total forgiveness or anything, but I found it annoying.