Good for him. As Henry Miller said, “I am a citizen of the world.” To the extent that everyone thought that way and abjured nationalism, tribalism and xenophobia, we’d all be better off.
To the extent being a "citizen of the world" is even possible given the state of the world today (and that's an issue for another thread), what Mama Mamdani said is not this. She said that he was not Americanized at all, and sees himself as Indian and Ugandan only. That is the opposite of what Henry Miller said. A "citizen of the world" would not abhor being identified with the place he made his home; he merely would not identify
only with that place. Btw, Papa Mamdani is a big apologist for the Ugandan dictator (and notorious cannibal) Idi Amin.
I notice you have pointedly ignored my posts on the harmonious diversity of views and ethnicities in NYC, which has nearly a million Muslims, as well as the study showing that the vast majority of Muslims in the UK are very content to assimilate but face constant discrimination,
I am not saying that all Muslims fail to assimilate, but a relatively high proportion of them do fail at that. In NY as in UK, and everyplace else.
And a small, but very disproportionally high, portion of those engage in violence, including in NY (subway bombings, the "truck of peace" attack) even discounting the 9/11 attack and the original WTC bombing.
The violent ones are the tip of the iceberg. The Islamists who seek to spread Islamic control through immigration and hypernatalism are below surface and pose a more insidious and in long term a far greater threat.
I count Siraj Wahhaj, whom Mamdani recently praised, firmly in the latter category. He wants an Islamic theocracy instead of democracy, but is not going to engage in violence himself. He did support the mastermind of the original WTC bombing though.