So people that engage in colonialism end up doing similar crimes. Israel remains probably the only old school colonial project in the present day with present day technology, backed by the U.S. empire to secure geopolitical interests in the oil-rich region among other things.
Something to think about: America is also a genocidal settler-colonial project and is one of the only nations to back Israel in the UN. Our genocide is still ongoing: visit a native american reservation and witness the immense poverty. Similarly to Gaza, the US state will simply say that despite being an occupying power, these are autonomous zones and we have little responsibility.
It does not absolve many, including self-proclaimed Zionists, from criticizing some of Israel policies.
On other hand, my interpretation of people who are self-proclaimed anti-Zionists logically flows from above statement that they believe that the present state of Israel DOES NOT have a right to exist. Which implies deportation of extermination of 6 million Jewish Israelis
In my opinion, the word Zionism has been hijacked by activists who know that being anti-Jewish is not good optics, but anti-Zionizm is still something that can be sold to the masses.
This argument is used to shutdown legitimate criticism of a multi-generational occupation, land theft and discrimination. Those things are not inherent to being Jewish. So the distinction holds.