The Holmes Family portrait

Little Sherlock and his family in a photo. Poor scared darling.
I personally don't think Sherlock Holmes had very abusive/overly religious/cane using/child molesting parents. I believe they were just a bit artistic and odd. Just like he is himself.  The fact that they are never mentioned in the canon doesn't necessarily mean anything dramatic, I mean, would you like to go on and on about your parents-in-law in you bestselling stories? ;)