No, the reason is much simpler. It's because God removed all the clear evidence that would undoubtedly prove the flood. He only left evidence that could be interpreted in different ways, with or without flood.
I am really uncomfortable with this line of reasoning.
Or at least the way it is stated.
It is defensible, but it is too easily abused by the prosecution (evolutionists). The practice here is to pillory people when the opportunity presents itself and not to take the time to find a way to assume the best of someone making a post like yours. I am not being critical. I am just a veteran of dealing with evolutionists and what they do with posts like yours.
Clearly, when God acts, there are multiple reasons that can be ascribed.
God creates satan for a number of reasons (or consequences):
1. as worship leader
2. to be exceedingly beautiful
3. to afflict Job with boils
4. to harden Pharaoh's heart
5. to deceive the nations
Similarly, God created a huge mess known as the flood. In destroying the old world, a lot of evidence went by the wayside. The announced purpose was to cleanse the earth, not muddle the evidence. But, as you suggest, it certainly had that effect.
Because you stated things as you did, it seemed to me that people would charge you with ignoring the complexity of the situation. That would be unfair and your post wouldn't require it.
It does seem clear to me that there is evidence for both used in the geologic column. I don't think you excluded that view. That would follow from the mere fact of the catastrophe in view. Whether one conclusion should be preferred from looking at all the evidence is a different question and one that we focus on human prejudice, not just the evidence.
One day, when all the evidence is in, only one conclusion will be supported by all of the evidence. The reason why humans made the wrong decision about it will have something to do with their prejudice, not that the evidence was impossible to discern. I assume you are not saying that God made it impossible to discern the nature of the flood from the evidence.
If you look at the story of Exodus, both types of causes and effects are in evidence. Pharoah clearly hardened his own heart by unbelief and rebellion. God also hardens his heart. Pharaoh's enchanters, conduits for satan, help him along.
Exd 7:3 And I will harden Pharaoh's heart, and multiply my signs and my wonders in the land of Egypt.
Exd 14:4 And I will harden Pharaoh's heart, that he shall follow after them; and I will be honoured upon Pharaoh, and upon all his host; that the Egyptians may know that I [am] the LORD. And they did so.
Exd 7:3 And I will harden Pharaoh's heart, and multiply my signs and my wonders in the land of Egypt.
Exd 14:4 And I will harden Pharaoh's heart, that he shall follow after them; and I will be honoured upon Pharaoh, and upon all his host; that the Egyptians may know that I [am] the LORD. And they did so.
So, this supports your post.
The old christianforums canard is that an honest, credible God would never give nature the appearance of a lie. This is stupid, since all the evolutionists here say that the old testament factually describes a flat earth. Or in other words, God would deceive lots of people in the past, but not evolutionist, because they are special.
However, it is quite clear that evaluation of the evidence represents three types of things: 1. where your heart is, there will your treasure be also; 2. God has hidden the truth from the wise and revealed unto babes; and 3. satan has been released to deceive the nations and snatch away the Word of God.
Of course, God could just speak the truth by trumpets from heaven. But, He has not. Why not? Your post suggests an answer.