Probably one of the poorer arguments that I think Arminians use is what is often referred to as the robot analogy. And I don't think it is poor for the reasons that Calvinist do. Calvinists seem to believe that it is inaccurate. Here I disagree: it is completely accurate. The problem is that if a Calvinist would simply own up to it, it would actually work to their defense... kinda. We can see this if we replace the notion of robots with action figures.
Now Calvinism's primary weak point is theodicy. Yes I know that Calvinists have a lot of answers to theodical questions, but that is because there are so many theodical questions which Calvinism invokes, and it is questionable if any of these responses really satisfy the objections. But let us consider Piper's argument that God brings about evil for the sake of demonstrating His glory. Now, in part, I think this doesn't really make sense because A)who is God demonstrating His glory to and B) the idea is really based off of 18th century political theory (if Grotius taught about the governmental theory of atonement, this argument can be called Edwards's governmental theory of election).
However, when I switched the word 'demonstrate' with 'express', it conjured up the image of myself as a young boy playing with action figures. At the time, I was really into He-man. Now, often I would have Skeletor kidnap my sister's Barbie, and He-man would come rescue her (my sister often played this with me). Skeletor's base was in the closet on the third shelf or so. As he and He-man fought, Skeletor would be cast off of the ledge into the abyss of the bedroom floor, receiving his just reward for his treacherous activities.
However, did Skeletor actually deserve what happened to him? After all, he only did what I made him do. Indeed, the Skeletor figure was completely impotent unless I caused him to act. So who's really to blame, Skeletor or me?
But if it is me, then have I, as a 6 year old child, done something wrong? Clearly not. My actions were expressions of my sense of justice. The fact that I ultimately desired He-man to be victorious shows that I was indeed just. Though I caused Skeletor to kidnap Barbie, I only did so for the purpose of He-man vanquishing him. I can't express my sense of justice unless there is evil for justice to act upon. Therefore, that justifies the evil that I committed, correct? That is the Calvinists point! That is their argument after all. It is proven.
Except when I did this, I used action figures. Action figures have no worth apart from my use of them. To really get to the point, both Skeletor's and He-man's ultimate destinies were the same: some trash heap somewhere, long forgotten if not for a blog post written many years later. In the end there was no true justice.
There was no true evil either. After all, Barbie didn't suffer. Nor did she suffer indignity. Indeed, there is no standard of morality which would claim that something evil had taken place. The reason why I am not evil has less to do with the line of causation of the action, and more to do with the reality of the action itself. It was merely simulated evil.
I think this is why Calvinists avoid the robot analogy. If accepted, it actually satisfies their need for protecting God's goodness and character. It supports their argument. But in doing so, they sacrifice the relevance of reality. It turns all of our lives, and all of God's actions in history as merely a show: a simulation for the sake of God working out His thoughts on the question of justice. This would apply not just to the acts of evil, but also to the acts of good and glory. Every endeavor of history, either human or divine would be destined to irrelevance, designating God's actions of salvation, power, mercy, wisdom, creation, and wonder as nothing more than a really well articulated play. I can't think of can't think of any more damage we could do to God's glory than that.