It was just an unkind jab at the fact that the examples given of exposure to different people and cultures were helping someone cross the road and giving up a seat on the subway. That jibed with my experience living in NYC - it's not particularly conducive to expanding your horizons; the diversity is there if you really want to go out and meet people, but mostly it will be courteous distance on the street and most of your deep interactions will be within your filter bubble, same as anywhere.
Unlike my current town, NYC has mosques, but I didn't actually learn anything about Islam or Muslims living there, compared to when I actually lived in the Middle East and made friends for life there. I ate at Chinese restaurants and shopped in Chinatown but wouldn't say I gained any cultural insights. But living in Singapore for a year and making friends with Singaporeans, Indonesians, and Chinese people - there I learned a lot.
I think you might be unduly defensive. I interpreted the "superficial" to mean "without the intimacy of an established relationship", which isn't particularly controversial afaict.
sorry why do you presume they're superficial? or i should sat why do you exalt your small town interactions over someone else's big-town interactions? i've lived in both a smalltown (currently) and brooklyn ny (previously) and the depth of the interactions is absolutely about the same.
btw we can all play presumptuous and haughty: in your "tight-knit" community no one will help you/acknowledge you as soon as you diverge from highly constrained cultural norms even a small iota - where as in my diverse working class neighborhood in brooklyn that wouldn't be the case. what do you say? not true? color me just as suspicious as you color yourself if i claim to you that i actually had deep and genuine conversations with my neighbors, grocers, and occasionally fellow subway riders.