As per the Mitchel Foucault's theory "Power and Knowledge. J. K. Rowling similarly conveys the message that question the power because what is written is not always true in the post truth era. Quote lines by Rowling is also Apt For The present era.
we see in many political leaders and media who keep on speaking lies for remain in the power and also there are many speeches or fake history. So, we have to cross check everything rather than follow blindly. Like ghotoism ....
Harry Potter, the novel conveys the message which is don't like by reader and many who watched the movie. Because protagonist, the half blood Prince ,Who wins over the pure blood, which can be not digest. And what can be assume about media and press it can not be truth also.
I think that what is said in this image is right. Harry Potter books do argue for intolerance and do plea to end bigotry. Dobby as free house elf also speaks to end the class discrimination. Further, yes, this can be the reason why people don’t like the books. But as the image says that it pass on very healthy message which younger generation should know. People always believe that to question authority is disloyalty towards authority. It's not disloyalty, in first place; and in second place, in democracy people have right to ask question to authority and to know things which authority is doing. So asking question is not disloyalty.
We live in post – truth era, so to doubt or to not believe without evidence should be the habit of people. We see that in Harry Potter also how Rita Skater manipulate the truth. So we should also not believe what authority or media says to us.