For me, I feel they did a lot right and really did the best with advice they got from the experts in our area and era.
Once they had the diagnosis for my disability and realized how far behind it set me back in many areas, they were very focused - and very matter of fact - on closing that gap and then on pushing me to excel once I caught up in the academics. They have always made it clear they believed in my abilities and that my disability did not make me any "lesser" of a person (I met a woman my age with the same disability, and she could not believe how comfortable I was with myself because her parents made her feel ashamed about her disability). My father understood my love of sports and supported me through injuries and my mother really did try to understand. Books have a high value (my dad had a huge library built into their house) but so does exercise/sports. I know they had regrets about not spotting my disability earlier, but they hid that well while I was young, and really just kept looking forward.
wrong - well, a lot of what could be "wrong" is a matter of cultural, and as I get older, I understand the choices they made and the reasons. For instance, my mother used to worry about my weight - and it was from health perspective (being fit, not having heart issues or diabetes) but it was not something I could handle as a teen as easily. And they did not handle the sibling rivalry well(mainly on my older sister's part - it is quite one sided) due to my older sister's intense jealousy and lack of understanding that my parents are not from this country so their cultural values are not same as what my sister expected - that still remains a mess.
I never ran into being severely underchallenged because of the enormous gaps I had to catch up on, but I can see now that I am gifted (to what level, I don't know since my reports showed it kept going up as all the remediation took effect and to go from being years behind, end up in honors and AP classes, and double-majoring in college while training for 3-4 hours daily for a year round sport is an accomplishment).