Matthew 13:10-15 and Calvinism

While on a facebook forum I responded to a hyper-Calvinist who asserted that God works to actively harden men's hearts with an offhand, almost throw-away comment that seemed to surprise David "The Darth Vader of Theology" Ponter, and I thought, if he hasn't considered it, perhaps I had better write it down. 
The verse in question is as follows:

Matthew 13:10-15- "Then the disciples came and said to him, "Why do you speak to them in parables?"And he answered them, "To you it has been given to know the secrets of the kingdom of heaven, but to them it has not been given. For to the one who has, more will be given, and he will have an abundance, but from the one who has not, even what he has will be taken away. This is why I speak to them in parables, because seeing they do not see, and hearing they do not hear, nor do they understand. Indeed, in their case the prophecy of Isaiah is fulfilled that says: "'You will indeed hear but never understand, and you will indeed see but never perceive. For this people's heart has grown dull, and with their ears they can barely hear, and their eyes they have closed, lest they should see with their eyes and hear with their ears and understand with their heart and turn, and I would heal them.'

The typical Calvinist reading here is that in an effort to keep them from salvation Jesus conceals His meaning in parables, for were He to make His meaning plain to them they would understand and then be saved, and of course Jesus doesn't want to save the reprobate. This I submit, is a terrible reading, does not fit with everything else about the nature of Jesus' earthly ministry, and is only mentioned because the reader has a prior commitment to supralapsarianism. Rather, I think the thrust of the text is on the hardness of their hearts.

His listeners have dull ears and don't desire salvation, therefore He speaks to them in parables so that they may go on deluding themselves. It's explicit: "This is why I speak to them in parables, because seeing they do not see, and hearing they do not hear, nor do they understand."
Matthew then records that this is the fulfillment spoken of from old: "You will indeed hear but never understand, and you will indeed see but never perceive." This isn't an act of condemnation ahead of time, it's a description of what will happen, of what they will choose to do when confronted with the Christ. It's not a curse, it's a foreseen choice of theirs.
How do we know that? The proof is in what comes next: "For this people's heart has grown dull, and with their ears they can barely hear, and their eyes they have closed." They have willfully closed their eyes, they have chosen to turn their back on Him.
So why then do they close their eyes and harden their hearts, and throw their wills against Gods? "Lest they should see with their eyes and hear with their ears and understand with their heart and turn, and I would heal them." For were they to see Him, they would have to submit to Him, accept His truth claims, admit they are not God, admit they are depraved creatures who have no righteousness to bring to the equation.  In short they must in humility crawl to Him for His imputed righteousness. This they can not stomach, so instead they close their eyes and make themselves willfully stupid.  Therefore He speaks to them in parables, because the last thing they want is to have Him show them kindness and save them, so He obliges them.

This is the same thing seen in John 12:37 - Though He had done so many signs before them, they still did not believe in Him" No matter how much Christ showed His goodness to them, they chose to hate Him, and they did not believe in Him.
38 "so that the word spoken by the prophet Isaiah might be fulfilled: "Lord, who has believed what he heard from us, and to whom has the arm of the Lord been revealed?" 
In other words, by giving them every opportunity to accept Him, He proved that unless He regenerates hearts (the arm of the Lord being revealed) they will never accept Him.

John 12:39- "Therefore they could not believe. For again Isaiah said,"He has blinded their eyes and hardened their heart, lest they see with their eyes, and understand with their heart, and turn, and I would heal them." 
This is substantially similar to the Matthew account, except that the blinding is attributed now to God rather than them, but because the Matthew account says they have asked for this course of action we can no longer see this as a divine exercise of sovereignty apart from their consideration.  It is both God and men agreeing on a course of action, namely that He will give them the desires of their heart. All who ask, receive- they have asked for blindness, they will receive it.
The thrust of both of these passages are on the hardness of their hearts, rather than on the mission of Christ to destroy them. They, not He, are to blame.