This is a common method of attack against Jews and other minorities. Deny bigotry against a group as "not real" or "not significant" and gaslight those victimized by it, making it, the minority, responsible for the bigotry enacted against it. We see this on the right with their screeches of "playing the race card" and "oh, poor pitiful me, why can't I call Obama a chimp, they called Bush the Lesser a chimp?! Isn't that the real racism?!" Even here, I have had to fight off ignorant bigots who claim homophobia isn't real because people aren't "really" scared of gay people, therefore, no "phobia". Sound familiar? It should because it is along the same vein of those trying to redefine anti-Semitism as "bigotry against Semites" when that is clearly not the definition of anti-Semitism.
Is anti-Semitism sometimes misused? Yup, just like every other "-ism" and "-phobia". But, it doesn't mean it isn't real. Furthermore, when I see accusations of racism and sexism, transphobia, and sometimes homophobia, I see liberals step back and ponder "hmm, maybe I should let the affected group lead the way and reexamine my attitude/speech", but when Jews say something is anti-Semitic, gentiles leap into action and BLAME the Jews and our supporters, claiming they are the real victim, not the Jews. There is no call for introspection, just accusations of falsely claiming anti-Semitism, y'know, "playing the Jew card"!