So what's the general opinion on Goosefeather?

Finished Bluestar's SE pretty recently. I absolutely loved it and had tons fun reading it. One character that stood out the most to me was Goosefeather. He is such a unique character and definitely my second favourite grumpy medicine cat (second only to Yellowfang). But before I read the books, I actually have heard people mention how much they hate him. I don't really get it. Like I know he played a part in his sister's death and went nuts, but he played a very important role, and... In the end, wasn't he right about everything? (Except the whole clawmark sign, he definitely pulled that out of his rear.)

So I guess I'm just asking to hear some thoughts about this character!

(Art belongs to me. Don't use it. Thanks.)