Quite simply, I am wondering where the hatred comes from, i.e., what the basis of it is. One who is on the receiving end of it might understand my question perhaps better than you seem to. I do not personally understand some of the vociferous hatred I have seen and experienced of Calvinists by non-Calvinists. That's all.

So, you are perplexed over the hatred expressed by non-Calvinists toward Calvinists; if I have understood you right this time.

Personally, I think this hatred, to which I have been the recipient on more than one occasion

... comes from unregenerate hearts for the most part. For the minority that are regenerate the basis for their hatred is the same as the unregenerate due to the fact that one isn't instantly made perfect when the new nature is created by the Holy Spirit. There is that "old man", remaining sin with which one must war against while living on this present earth.
Specifically, although "Limited Atonement" is one doctrine that many rail against, the hatred is initially stirred up due to the Calvinist's doctrine of God. We believe that God is absolutely sovereign in BOTH
power AND
authority. It is the authority part which really raises the angst. Non-calvinists have little objection to a God who can be said to be "all-powerful". But when it comes to this all powerful God using that power according to His own will, then the rage appears. Now, I did say "initially" this doctrine of God brings out the hatred. But I do believe that the actual source of the hatred people have for Calvinism/Calvinists is over the doctrine of "Total Depravity". This doctrine removes any and all ideas concerning man's autonomy; aka: 'free-will'. It also disallows any idea(s) that would have man possess some kind of innate moral goodness, be it ever so small. So, the hatred flows most vehemently when you speak of man being totally destitute of anything good, that man is filled with nothing but evil and hatred for God and all that is good. And, when you speak of man as having no moral ability to do anything good; even to seek after that which is good, including God, this fans the flames. Finally, additional fuel is thrown on the fire when you insist that despite the fact that the fallen, natural man is born with a sin nature, he is not only wholly culpable for every sinful thought, word and deed, he stands guilty before God who is wroth with him, and that he is under God's judgment and destined to eternal hell unless God has mercy upon him.
Non-Calvinists have an insatiable desire to hold fast to their fallacy, "I am the master of my fate: I am the captain of my soul". They desire to have a "god" that is under their power, although they usually don't come right out and state it that way.

But at the end of the day, their "god" does cater to man's will. As I've stated here so many times, there is an old adage which describes this all too well:
In the beginning, God created man in His own image. And every since that time, man has been trying to return the favor.