I haven't heard people talk about Black Panther in person, but some of the hate is because white people in general benefit from black oppression, since they will get the job, promotion, notoriety, etc. first. It's also because most, if not all the characters are dark skinned, and white people have devalued dark skinned black folk, it originated in slavery days here in the U.S., internationally, I don't know where that origin oppression came from. It sounds similar to when Django Unchained came out, there was a lot controversy talk, and it was because of what Django was able to do to the slave owners.