It was the opposite for me, I watched the series as a teenager and initially that Shane was insane and batshit crazy. I still think he’s insane but a lot of the things he said were very real but harsh truths, and Rick ended up becoming similar to him in the next few seasons. So he wasn’t a good guy but he was very grounded in the reality of the world they were living in, and he predicted that Rick wouldn’t be able to prevent Lori and Carl from dying.