Greetings in that Divine and Most Precious name of Our Lord and Savior Jesus Christ!
Bro Gebre Menfes Kiddus, I think you are taking this all way to personal, and starting to get way too defensive. The folks are rightfully misunderstanding your unclear opinions regarding children's literature. You have been taking it way to personal, all you had to say was,
"Sorry guys, I don't like my kids reading Harry Potter" and left it at that and moved on to better discussions, instead you let your defensive reaction to defend your parenting get to you, when its nothing personal until you make it that way. So let it go, these folks are just trying to understand you, but you are not really explaining yourself very well, so just quit while you are ahead.
In regards to literature in general, I would like to reiterate this point I made earlier which got lost in all the bickering..
Novels and literature capture in subtle detail the full gamut, not just of the full range of the human experience, but also our contemporary realities. This precisely why in all grades in public education, we expose them to literature, that they can experience for themselves the growth and learning we get from reading fiction, because to understand fiction is to understand the underlying reality it portrays. Further, fiction gives kids an opportunity to ask real, deep questions about our societies, our cultures, our moralities, our histories, our realities that is safer and more mutually neutral than confronting these same kinds of issue in real life. Novels can critique and explain reality in ways lectures simply can not.
I believe in protecting but not sheltering children. After all, no family is an island and kids are not stupid. We can't honestly expect to shelter them from the ills of our societies unless we literally shelter them, and that is not exactly healthy or even necessarily Christian (see John 17:16-18; Mark 16:15-16). I mean no disrespect to parents out there, but we all need to be a bit honest with ourselves and have a bit of a sense of humor about some things too. If we shelter our kids from reading, learning, and experiencing certain things for themselves, we are also blocking some opportunities for spiritual growth, development, and maturation. We can raise our kids righteously without having to keep them in a bubble.
Me personally, I believe in being totally honest with kids and letting the cards fall where they fall, after all, kids are people too and their often some of the brightest people I meet and know 
"You can't blame the youth of today, no and you can't fool them." Peter Tosh
stay blessed,
habte selassie