‘Criticism of Israel, and support for the rights of the Palestinians, is entirely legitimate.

Criticism of rhetorics (or actions) which contravene to Common Rules (i.e. International Law, Human Rights, International Conventions) is perfectly legitimate.

In addition, in case someone claims that the State of Israel is a Democracy, it is legitimate to criticize this opinion. Indeed, the Declaration of Independence of Israel mentions Democracy and explicitely say that no discrimination of any kind will apply between the citizens. But, there is a dissymetrical citizenship for Israeli Arabs (they can vote, but the State is not theirs). Also, they have great difficulties to buy/rent land (because of the “Zionist-Jewish” nature of the land within Israel). There are also many other discriminations: ( https://www.adalah.org/en/content/view/7771 )