If Harry Potter HAD been written about child abuse...
it would have been a heavy-handed treatise that didn't sell.
A popular book must be, above all, popular.
FIRST capture the audience, THEN try to sell them a story.
If you do it the wrong way round, you are doomed to rejection.
I'm not dismissing your point of view. I can see that you feel strongly about this. But above all, Harry Potter is a series about a boy that children can empathise with. They share his feelings of (un) fairness, honour, and adventure. There are some important messages that ARE getting across. If you compromised the delivery by getting heavy-handed, you'd burst the bubble and destroy the WHOLE information delivery process.
"The Perfect is the enemy of the Good". Beware the Perfect...