Sorry, my other comment skipped this question. What I mean by anti-Semitic criticism is criticism motivated by anti-Semitism, and, separately, criticism that attempts to exploit the emotional weight of the Holocaust (e.g. "the Zionists are the new Nazis" or subtler variations thereof).
The former of these might be legitimate criticism in some cases, yes, but tends not to be, and even when it is, bear in mind that most people are totally clueless about the world. If Joe Sixpack hears ten times as much criticism of Israel as Saudi Arabia, he'll assume that Israel is much worse than Saudi Arabia, even though this is clearly not true (unless you happen to be a Wahhabi Muslim, I guess). I remember hearing of a survey conducted in China where Chinese on the street were asked how big they thought Israel was and some answered that it was probably about as big as China. I can't find it, but I did find an article where the Chinese ambassador to Israel describes something similar: "I explain to [other Chinese] that Israel only has seven million residents – barely a small town in China," he says. "They find it hard to believe. I understand them." (source: http://www.ynetnews.com/articles/0,7340,L-3961612,00.html)
And for the third time, I don't think it's a good test and I don't really like being put in the position of defending it. My mention of it was descriptive, not prescriptive.
I got thrown off by the terminology "anti-Semitic criticism". From the context it seems to mean: criticism by an "anti Semitic" person, you probably meant "criticism that has no truth in it". Why cloud matters then, with terminology that is already too loaded to begin with ?