Some people like to speculate on God's reasoning when something that they consider to be bad happens to them. How often do these same people speculate on God's reasoning when something good happens to them? Asking God why when something bad happens presumes that we were undeserving of our misfortune. It also presumes that we deserve any good thing that God grants us. Neither is the case.
I recently had someone speculate to me about why God would give me two autistic children. The thesis was that God must have known that I would be a good mom to my kids and that my experiences would help other parents. Now I am a good mother (if I do say so myself) and my experiences may be helpful to others but I don't see any point to speculating about why I have autistic children (aside from determining cause and possible avenues for treatment) except to make myself feel better about what is most definitely a stressful situation. (There also seems to be an assumption that this is a bad thing. Yes my life is difficult and the boys will have challenges to over come but who's to say that their being autistic is not a blessing?) Why wouldn't God give me two autistic children?
How often do you hear someone speculate about why God allowed them to wake up in the morning? Or why God gave them a roof over their head? Or provided them with good health and daily sustenance? Just about never. Why? Because we consider these things to be our due. If we were a little less self centered I think we'd realise that we don't deserve any of the good in our lives.
All of creation is corrupted by the sin of mankind. In light of this corruption the unpleasantries of life are par for the course. It's not really perplexing that we have to deal with things like autism. It is a consequence of that whole business back in Eden. This is not to say that we should turn a blind eye to the suffering of others because they brought it upon themselves with their sin. Far from it. It most certainly honors God to try to alleviate the suffering of others. We won't always succeed but we can try.
What is perplexing is that God allows any of us to draw breath in the first place. I often find myself wondering just that. We rape, pillage, and kill but God still hasn't wiped us out of existence. Why? Always, before I can even complete the thought, the answer comes back, because he loves us. Because God loves us he lets us live. Because God loves us he gives us the opportunity to be spared the eternal consequences of our sins. Because God loves us his son willing went to the cross to buy us that opportunity with his life. That kind of love is stunning. It leaves me breathless.
So I don't speculate about why when things don't personally go my way because God has already spared me from the most devastating of fates (eternal damnation) which I surely deserve and given me something that I most certainly did not deserve (salvation).