I think some of the angry responses on the part of Calvinists to Arminians has to do with the moral objection to Calvinism that Arminians often use, which sometimes is expressed by the claim that the Calvinistic God is as bad or worse than the devil.
This is tricky and something I should probably address. I take it Calvinists say that the actions of Satan are predestined before the foundation of the world by God. That being the case, if you buy into the kind of incompatibilist theory of moral responsibility that an Arminian typically does (responsibility is traceable to the originating cause), then God is responsible for everything the devil does. Given this picture of things (and an Arminian might agree with Kant that compatibilism is a "wretched subterfuge"),
Now Calvinists think that intermediate causal agents are responsible for their actions, and, at the same time, God does have a good reason for predestining Satan to perform all the evil actions he performs, including those actions which cause people to sin their way into hell. So, God is in the clear, and Satan is not.
Working from their own understanding of moral responsibility, it is easy to see why Arminians can end up saying "Your God is the devil." The Wesleys did that, and it cost them their friendship with Whitefield. Put thus, the objection puts the Calvinist's back up, and things tend to get acrimonious from there.
Maybe the Arminian should say "Given our understanding of who is responsible for what, an understanding we consider to be the fact of the matter, the Calvinistic God turns out to be as bad as the devil." I think that is not quite the same as saying "Your God is the devil."
As strongly as I object to Calvinism, I see no good reason to suppose that Calvinists did not come to be Calvinists out of a Berean intent to search the Scriptures to see if these things are true. Of course there are psychological motives on all sides that are not transparent even to ourselves, but I have no more reason to doubt a Calvinist's account of why he is a Calvinists as I am to doubt an Arminian's account of why he is an Arminian.