Bashing the State in front of non-Jews is a Mitzvah in order to educate the non-Jewish world that the State does *not* represent Judaism or the Jewish world, as the State and Prime Minister often falsely claim to represent on the world stage.
By educating the world that the State’s position is a false narrative, we can hope to mitigate the negative reaction of the world when the State of Israel does harmful and reprehensible things, from the world blaming Israel’s badness on Jews in general, since the State of Israel falsely claims to represent world Jewry.
But all of that is aside from your demonstrably false claim that the Rov is affiliated with NK. He is not and never was.