Saying "anti-Zionism is anti-semitism" is just saying you want more anti-semitism. Insisting that everyone erase the distinction between people who happen to be Jewish and people who support a genocidal apartheid state is saying you want more people to hate Jews. The harder you make it for everyone to hold that distinction, the less that distinction is going to be made.
If you insist that everyone needs to choose between hating Jews and supporting genocide, a lot of people are going to choose to hate Jews. It's not a choice that actually needs to be made, but a lot of Zionists are insisting that everyone has to choose.
Anyone who says anti-Zionism is a hate movement is a lying, manipulative hatemonger. Making a distinction between Judaism and Zionism is a good faith effort to REDUCE hate. Everyone who insists on erasing all distinctions between the two is working to increase hatred of Jews.