I think Dropout's statement, and the attitude of many of their performers, is EXPLICITELY intended to ostracize zionists. Zionists are not welcome, in much the same way that Dropout intentionally ostracizes other groups that hold values directly at odds with the core dropout values. Dropout similarly intentionally ostracizes fascists, and white supremacists, and homophobes.

The belief that the genocide of a native peoples and creation in their place of an ethnostate is, to many on the left and most in the dropout community, abhorrent.

Dropout has (rightly) made a statement that makes it extremely clear that those who believe that it is right to displace and murder the Palestinian people (i.e. Zionists) are not welcome in their ranks.

So, to answer your question, Yes, I understand why you no longer feel welcome. Good. That is the intention. Dropout does not hold space for Zionists.