I agree that the abuse doesn't have to be sexual or even severe to create DID. There have been other cases where a young child has experienced ongoing relational trauma with no adult support and developed DID. But in my experience (limited to online forums and in books and articles) severe abuse (very frequently sexual) is the main cause of it.
I know you believe differently Michael but I haven't seen your scenario play out much in literature or self reports online.

I didn't see anything alarming that might indicate they were trying to discredit DID at all. Not at all. I thought they approached it sensitively and appropriately.