The problem is it puts God in 100% responsibility for evil and for every horrendous thing that has ever taken place on the earth. Rather than Him "not knowing" He "knows" the complete future. He had a choice to create or not create, or create differently. Platinga argues this is the best of all possible worlds in an attempt to answer this problem. I disagree, there are better possible worlds. And while his philosophy stands up against criticism, it is the conclusion that one can refuse at face value if presented with a better systematic theology i.e. Open Theism.
Whenever there's a discussion about doctrines such as Free Will, Sovereignty, Predestination, Foreknowledge, etc I usually try to urge the participants to avoid nebulous theoretical concepts and focus instead on applying whatever they might believe to concrete biblical events where those beliefs can be tested practically. A good place for that are the events surrounding God's original promises to Abraham about his posterity eg, Gen15:13-16 which gives a definitive statement about God's predestined, sovereign will for the future nation of Israel - "God said to Abraham, Your descendants will be strangers dwelling as temporary residents in a land that is not theirs and they will be slaves there and will be afflicted and oppressed for 400 years. But I will bring judgment on that nation whom they will serve, and afterward they will come out with great possessions. You shall go to your fathers in peace; you shall be buried at a good old age. And in the 4th generation your descendants shall come back to Canaan again.."
When the time came, God sent Moses to that 4th generation (Ex6:4-6) "And God said to Moses, ..I have established My covenant with them to give them the land of Canaan, I have also heard the groaning of the Israelites whom the Egyptians have enslaved; and I have earnestly remembered My covenant with Abraham. Accordingly, go and say to the Israelites, I am the Lord, and I will bring you out from under the burdens of the Egyptians, I will free you from their bondage, and I will rescue you with an outstretched arm and by mighty acts of judgment. And I will take you to Me for a people, and I will be to you a God, and I will bring you into the land concerning which I lifted up My hand and swore that I would give it to Abraham, Isaac, and Jacob; and I will give it to you for a heritage."
God also sent Moses to Pharaoh in Ex4: 22 saying "Thus says the Lord, Israel is My son, My firstborn. So I say to you, Let My son go so that he may serve Me"
And although the Israelite's response to Moses was - "Let us alone; let us serve the Egyptians. It's better for us to serve the Egyptians than to die in the desert (Ex14:12}", despite those misgivings, God sovereignly delivered them from bondage and took them to the Promised Land according to His promise in Gen15, but when He commanded them to enter the Land they refused and 40 years later, the 5th generation entered instead.
To summarize: God gave a sworn promise to Abraham that He'd bring the 4th generation of Israelites into the Promised Land and when the time came He sent Moses to that generation (who He called 'His son'), expressed His concern for their bondage, repeated the sworn promise to them and then did exactly what He promised Abraham- sovereignly saved them from bondage, brought them to the Land, but when He commanded them to enter and possess it, they refused and were instead destroyed. Rather than the 4th generation entering as originally sworn to Abraham, it was the 5th.
Determinists, Calvinists, and anyone else who subscribes to unbiblical definitions of doctrines such as Sovereignty, Free Will, Eternal Security, Election, Predestination, Foreknowledge, etc can't reconcile their doctrines with these verses - for instance, (1) if God sovereignly predestines all things irrespective of man's will as Determinists claim, then how did the 5th generation enter the Land instead of the 4th as God originally swore to Abraham? and (2) When God sent Moses to the 4th generation expressing His concern about their bondage and promising them a new life in the Promised Land, was He secretly intending to destroy them in the desert, just as they feared?
Such practical events are a good place for anyone to test drive their theories to see if they can actually be reconciled with reality instead of spending endless and usually fruitless hours arguing about them in abstracts.