I remember watching a movie a while back about a guy whose wife and children were all killed except one, and that child was injured in the attack and suffered a disability from it for the rest of his life. A few years later, the child (now in elementary school) was kidnapped by Cthulhu-esque monsters and imprisoned with a bunch of much older characters. This kid ends up initiated into their weird cult-like organization and attempts to escape with them by sabotaging their own prison, but it ends badly and the kid almost ends up killed. Meanwhile, the father goes on a rescue mission, aided by a crazy amnesiac lady who would be more hindrance than help except that she’s the only one with information on the monsters. The erstwhile couple nearly get killed several times over by various abominations (most of whom are trying to eat them), are briefly aided by a group of serial killers, and only end up at their destination through the help of a Leviathan-like creature). The father briefly sees the son dead (actually playing dead to escape one of the Cthulhu-esques), panics, and starts heading home in despair, but the son manages to escape and run into the crazy amnesiac lady, who’s completely forgotten who and where everything is. She snaps back to a modicum of sanity and reunites the father and son, but ends up caught in a trap with several hundred other characters, who only barely escape. At the end of the film, the rest of the prisoners who were with the kid escape, but they botch the job and it’s implied that they all die. (Thankfully, the sequel proves this wrong.)
You know what movie this is?
Finding Nemo.
The inclusion or exclusion of specific elements of a work by themselves does not validate or invalidate them. A lot of it is contextual and depends on the genre, what’s expected of the genre, how the elements of the story world are put together, etc. I haven’t read any Harry Potter myself (I’ve never really been that much of a fantasy guy), but I know several (hundred) people who have read it as children and it doesn’t seem to negatively affect them.
Feel free to make your own judgment on the issue though.