Haters are gonna hate is all I can say. I mean there are people who just hate things just to hate them, there's those who have reasons to hate things, and then there's those who have "reasons." I mean I see this no different from those who are homophobic and such. Do I think it's fair? No, but when has anything in this world been fair? It's a world of two knights clashing, one always trying to gain the upper hand of the other. Fairness holds no water in this world, it seems like it should, it would make sense if it did, but it's a bowl made of paper, that would soon cave in because facts and logic aren't what makes decisions, it's emotions and opinions.
I think you're missing the point.
The difference is that Westboro hasn't tried to kill a few hundred people with poison gas. This isn't a matter of fair and unfair. This is a matter of right and wrong, and the overwhelming majority of people do not feel that this is acceptable in any way. Yes, haters will hate, but the problem isn't that there are haters. The issue, which you seem to be downplaying, is that these haters have committed a crime. As much as I hate Westboro, they haven't done anything but exercise their freedom of speech. Attempted murder is not an expression of free speech, which is why we aren't downplaying the issue.