When people criticize God's behavior in OT times as horrific, they are usually thinking more of him killing babies and individuals that may not have been particularly evil. When considering God today, no one is suggesting that he should start killing babies again. Rather, they are asking why God doesn't stop crimes that any decent person would stop, e.g. if you saw someone getting attacked on the street you would try to stop it (call the police, try to disarm the attacker, etc.).
Oh yes I understand that of course and I myself also find my self asking why too, as do most believers I assure you.
ANd I am sure that you are familar with the arguments as to why God doesn't interfer ( free will and all that other stuff).
My point is that we tend to blame God for acting in the past but some tend to blame him for not acting in the present in a way that THEY want Him to act.
That just doesn't make any sense to me, even though I can sympthise with that view.