If you're so sure that is "isn't because it isn't biblical" then why aren't you a Calvinist?
Let me tell you that Calvinism flat out is NOT biblical and if it were, not only would I refuse to be a Calvinist, I would refuse to be a Christian! It could not be any more unbiblical if it made the attempt! It is 100% rooted in Classical philosophy. If Aristotle hadn't taught that God was Immutable, you wouldn't believe it and Calvinism wouldn't exist at all. The absolute immutability of God is THE singular pillar upon which all of Calvinism's distinctive doctrines rests. Everything from Total Depravity to the Preservation of the saints and everything else you think of as Calvinism is derived logically from the idea that God cannot change in any way whatsoever. All of which has been established hundreds of times on this site alone.
This particular thread is focusing on justice, however, and so let's stick to that issue in particular. You said....
Well, how could it not be?
First of all, Calvinism does not teach that God leads the elect anywhere. The elect, according to Calvinism, is saved by virtue of having been elected not because they were brought to a place where they could "see the light" and choose God. Nor do they believe that God elected them because He foresaw their choice. They believe that God's election was arbitrary.
“God is moved to mercy for no other reason but that he wills to be merciful.” (John Calvin, Institutes of Christian Religion, Book 3, Chapter 22, Paragraph 8)
“… predestination to glory is the cause of predestination to grace, rather than the converse.” (John Calvin, Institutes of Christian Religion, Book 3, Chapter 22, Paragraph 9)
“Therefore, those whom God passes over, he condemns; and this he does for no other reason than that he wills to exclude them from the inheritance which he predestines for his own children.” (John Calvin, Institutes of Christia/n Religion, Book 3, Chapter 23, Paragraph 1)
“We cannot assign any reason for his bestowing mercy on his people, but just as it so pleases him, neither can we have any reason for his reprobating others but his will.” (John Calvin, Institutes of Christian Religion, Book 3, Chapter 22, Paragraph 11)
“But since he foresees future events only by reason of the fact that he decreed that they take place, they vainly raise a quarrel over foreknowledge, when it is clear that all things take place rather by his determination and bidding.” (John Calvin, Institutes of Christian Religion, Book 3, Chapter 23, Paragraph 6)
"All are not created on equal terms, but some are preordained to eternal life, others to eternal damnation; and, accordingly, as each has been created for one or other of these ends, we say that he has been predestinated to life or to death. (John Calvin, Institutes of Christian Religion Book 5, Chapter 21, paragraph 5)
I want for you to be sure and read those quotes. Those are not aberrations! Those are not things that Calvin himself believed but that Reformed Theology does not teach. That IS what Calvinism teaches and no one who denies the truth of those statements can rightly call themselves a Calvinist.
In addition to that, Calvinism teaches that those who are arbitrarily passed over and thereby condemned to Hell forever are so condemned for actions that God unchangeably preordained that they would perform!
“The devil, and the whole train of the ungodly, are in all directions, held in by the hand of God as with a bridle, so that they can neither conceive any mischief, nor plan what they have conceived, nor how muchsoever they may have planned, move a single finger to perpetrate, unless in so far as he permits, nay unless in so far as he commands, that they are not only bound by his fetters but are even forced to do him service” (John Calvin, Institutes of Christian Religion, Book 1, Chapter 17, Paragraph 11)
“thieves and murderers, and other evildoers, are instruments of divine providence, being employed by the Lord himself to execute judgments which he has resolved to inflict.” (John Calvin, Institutes of Christian Religion, Book 1, Chapter 17, Paragraph 5)
“But since he foresees future events only by reason of the fact that he decreed that they take place, they vainly raise a quarrel over foreknowledge, when it is clear that all things take place rather by his determination and bidding.” (John Calvin, Institutes of Christian Religion, Book 3, Chapter 23, Paragraph 6)
“We hold that God is the disposer and ruler of all things, –that from the remotest eternity, according to his own wisdom, He decreed what he was to do, and now by his power executes what he decreed. Hence we maintain, that by His providence, not heaven and earth and inanimate creatures only, but also the counsels and wills of men are so governed as to move exactly in the course which he has destined.” (John Calvin, Institutes of Christian Religion, Book 1, Chapter 16, Paragraph 8)
And again, those quotes of Calvin represent normal Reformed doctrinal teaching. That is what they believe and teach. Indeed, it was they are forced to believe and teach if they desire to have a doctrine that is rationally consistent with their foundational doctrine of Immutability. They literally choose to render the term "justice" meaningless in order to preserve their understanding of what it means to say that God does not change.
Alright, that's enough for now. I could keep going for thousands of words but I'll let you digest that for a while and we can contiue in any direction you pick to go in.
Resting in Him,
Clete