The problem is that the morality is relative.
For example, torturing someone (using illegal, prohibited means) because they killed your godfather.
Now a truly moral tale might involve such a use by the protagonist, but it would also involve the person in question being punished with the appropriate consequences ( in the case of the crucius curse, that would have been exile to Azkaban) or at the very least, the protagonist expressing a level of remorse approproiate to the moral wrong.
Neither happend with Harry.
What is presented instead is that if an evil person kills a relative of yours, that person may be tortured without repercussions. I’m not convinced that such a message is appropriate for kids.
For example, how many of us would be comfortable with a novel where the protagonist, Harry Carpenter, tortures an Al Queda operative with a taser because he killed their godfather.
Or is does the fact that imaginary means ( curses) are used to torture justify the message?