When it come to fancy new public transport or malls or other infrastructure, it's normal enough that countries that have been prosperous for a long time have less of the super-modern stuff than the newly developing countries - since those prosperous countries got all these things decades ago, and as long as it's relatively functional it isn't worth replacing by brand new stuff (especially since replacing such things often creates a great deal of discomfort while the replacing is under way).
That, and not all of the US is as dirty as NYC. It's an amazing city in many ways, but most of the returning tourists do comment on that aspect of it...
And lastly, when it comes to the extensiveness of public services (be it the regularity of trash collecting, the number of trains per hour or the amount of cleaners in a mall), low-wage countries do have a considerable advantage in making these things much more affordable (in much the same way that in the US countless stores can afford 24/7 opening hours while in Europe it's much rarer - while American wages are more likely to be higher than lower, American labour does tend to be cheaper due to lower taxes, social security etc.).
Of course, I do agree that some differences are really cultural and not so easily explained by simple economics - people in some countries are simply nicer and more courteous than others, and any tourist will notice the difference. Though in that regard I've never had any reason to complain about the States; the good much outweighs the bad. Perhaps slightly less so in NYC, though.