If you wish to pursue the Dark Arts, of course, that's up to you.
No dark arts for me, thanks.
Children are influenced by what they read, see and hear. They immerse themselves in the worlds created in books. Parents need to discern what influences they want their children to have. They should carefully read what their children are going to read, see what movies or TV their kids are watching.
If they don't, they shouldn't be surprised when their kids grow up with beliefs or behaviors they didn't expect or hope for.