What's funny is that if read between the lines of Keller and Power's reviews, it's not that hard to see why they didn't like it. They both bring up the same issues: run time drags, the middle is bogged down by a dialogue/exposition-heavy drama regarding Wakanda's politics, the action sets are fun to look at but separated by aforementioned throne drama, the actor who plays T'Challa does a good job but is held back by the task of "elevating the superhero genre" and the throne drama so he isn't allowed to be the kind of quip-machines people have come to expect of Marvel characters, and that the movie itself can't seem to decide if it wants to be super cereal or a fun popcorn flick and the scenes feel disjointed as a result. Those are mild but not exactly uncommon criticisms to have, they aren't even uncommon criticisms to have about Marvel movies as of late.
But no Black Panther goes down 2 whole percent and suddenly it's a conspiracy by the evil embittered whitey to ruin the movie and inflict violence on defenseless black people everywhere with fraudulent reviews and RT needs to censor/ban these subversives; not for any actual racism, but because their opinions conflict with their vision of Black Panther being this perfect untouchable "woke" film sticking it to Trump.