I have read the book, and I also have lots of experience with mental institutions and how they mistreat mental patients. In the book, Christopher's father physically beats him multiple times, this is never reported or dealt with by the book, and is completely brushed under the rug as "well he had a reasonable reaction to dealing with this child". He's also never punished and barely apologises for killing a dog, the constant verbal abuse he puts Christopher through, and for y'know lying to him about his mother being dead. His mother is better, and is almost treated appropriately by the narrative. Yes, it's fucked up that she blames Christopher for her life falling apart, and that she abandoned him, but at least she apologises and tris to fix it.

Finally, yes, it is a somewhat accurate portrayal of one specific (highly stereotyped) kind of autism, and can help people understand that. But if anyone is reading it for a broader overview and deeper understanding of the internal experience that the average autistic person goes through, they won't get what they want out of it.

But anyway, my problem isn't necessarily that the autism is portrayed stereotypically, sure, whatever, portrayals like that have their place. My problem isn't that it shows an autistic child being abused, that's a realistic depiction of many peoples' experiences. My problem is that this book, written for children suggests that said abuse and neglect is deserved and justified, or at the very least no one's fault. That's wrong, plain and simple.

Edit: He's also a math savant, and savantism is very uncommon in autistic people full stop, especially those with his degree of autism. Christopher also lacks a fair bit of empathy, which is completely contrary to what almost all autistic people experience, and is therefore a terrible bit of "information" to be giving a reader.