Bike Snob has an excellent review and analysis of NYC's biking needs.
I feel compelled to concur that yes indeed there are differences between biking needs in Amsterdam and NYC.
There is the false belief that "Amsterdam" bikes have to be heavy. No. They're not. The Ome Fiets (Grandma bike) is only one style. One I personally dislike because you can't ride aggressively. And no doubt Dutch grannies would, if only they had better bikes.
Batavus, for instance, builds lots of good city bikes that are light. Too bad they're all ugly.
In my mind, an "Amsterdam" bike has upright handlebars, fenders, chainguard, bell, and a rear rack.
But there are two main differences between biking in NYC and biking in Amsterdam. Amsterdam is flat. I mean so is most of New York City, but we have the high bridges and upper Manhattan. Amsterdam does not.
Amsterdam is small. Very small. Rides in center take 10 minutes. The Oos (East) in Amsterdam is kind of like Queens. It's soooo far. And filled with immigrants. And not at all cool. It's a great neighborhood. And about 2 miles from the center.
My relatively short bike ride to work here is 5 miles. In Amsterdam, that's the equivalent of biking from the center to Schiphol Airport, and unfathomable distance in the minds of most Amsterdammers.
So while riding slowly and singing is beautiful (and actually happens quite a lot in Amsterdam). That is just not the way I can get to work here in NYC.
Here's the link again to Bike Snob NYC.