Why do some people hate vegans that are critical of promoting Welfare "reform"/SIC's

Another post I wrote in the parallel discussion thread on a Facebook-page where vegans who oppose SIC's are critisized; and some people hate vegans who oppose SIC's:

I agree with the principles of Abolitionist veganism. This doesn't mean that I agree or condone with all of how any person acts on their Facebook-page. You need to be able to differentiate between principles and persons advocating for these principles.
I think it is profoundly sad that you compare other vegans to the hateful "Westboro Baptists". You criticize others of a behaviour you don't like, but then you restort to hating other vegans who have spent thousands of hours of educating non-vegans about veganism. How can you criticize others of being demeaning, when you are doing it yourself?

It is possible to be critical of other people's approaches, without hating or demeaning other persons. We can have arguments based on substantial arguments and still be friends.
I think anti-fur-campaigns are problematic based on the following reasons: http://bloganders.blogspot.no/2014/05/the-problem-of-focusing-on-anti-fur.html
I still think that people participating in these campaigns are well-meaning people and doing their best to fight for the animals. I just think that we always should advocate veganism, and not confuse nonvegans to believe that their is a moral difference between fur and other animal exploitation. After all - if we want people to go vegan, we shouldn't contribute to their speciesist confusion.