Being against a genocide perpetrated by the Israeli government is not anti-semitic. Calling it such actually makes Jews, who have suffered for millenia from anti-Semitism, less safe.

By conflating Irael with Judaism, the crimes of the Israelis are - by you - transferred onto the Jews. That is bad for Jews both short and long term.

By conflating Irael with Judaism, acts of real anti-Semitism (sadly plenty to be found) can be discounted as just another fake charge of anti-Semitism.