New York, a city I called home for two years in the 1990s, is not typically American, not in my eyes. It attracts a much more diverse segment from the US and the rest of the world. For the New Year's countdown, the crowd was predominantly youthful, similar to the one at Shanghai's Bund. Anyway, I would hesitate to draw sweeping conclusions from one event or a few photos of it. I've seen American downtowns much dirtier and scarier than Chinese cities, and American suburbs and small towns much cleaner than Chinese ones. There are many reasons for the discrepancy, but race or ethnicity is not among them as far as I can figure out.
As I see it, the outcry from Chinese netizens over the photos stems from ignorance. Those who do not know the US that well may imagine it as a symbol, either of goodness or of evil. As such, they would see the posting of the photos as a gesture of reluctance to face our own problems - or even one of denigrating the Utopia of their mind. I'm convinced those people have never lived in the States or read an American newspaper, which is usually plastered with local setbacks and criticisms of various policies.
Of course, there was also the camp of schadenfreude that, "They were no better than us". They used the photographic evidence to justify domestic problems, inadvertently bearing witness to the mentality portrayed by the old Chinese saying, "Those who run 50 steps away from danger call those who fled 100 steps cowards". They forgot that lessons learned in other countries can indeed be applied to similar situations in our own country, with qualification, of course, thus saving us the trouble of making the same mistakes.