Why are antis so stridant and unreasonable?

They have literally no argument. Logically communism just works. When you lay the facts out, however, antis will get riled up and threaten you while babbling about historical strawmen. To hear an anti tell it, communism leads to immediate mass death, like it's a plague rather than the most logical way to organize a society. Does anybody know why they get like this? Is it just the result of a low-IQ or is something more sinister going on?

Communism is a utopian vision. Yeah, it all sounds good in theory, everyone equal blah blah (and I'll leave the philosophical implications of "equality as golden standard" out of this); however, it ignores the fact that people NEED hierarchy. Without hierarchy there is no order in society, and since nobody is "above" the average worker, you end up with people doing whatever the fuck they want to.

"But wait! Society will emphasize the value of work! People will rejoice in a sense of community and responsibility! Love thy neighbour!"

Again, utopian. This only works in very small, independent communes, since the average person can only really care about and conceptualize the needs of ~150 others. On a national/global scale, the system falls apart. People are quite essentially selfish, and that fact needs to be accounted for in government. For all its horrible faults, capitalism is a strong system precisely because it takes advantage of this selfishness and uses it to encourage economic growth -- you are rewarded for your contribution.