The Manhattan streetscape is extraordinarily interesting, with countless intriguing and unique shop windows designed to attract the passer-by on foot. Even the street vendors, whom some city officials complain hinder walking activity by taking up valuable sidewalk square footage, actually help the pedestrian environment by offering more points of interest aimed at appealing to walkers.
Blocks are varied, windows are close to and looking out at the street, there's usually a good buffer between pedestrians and traffic (on-street parking works for this) -- and ironically, the fact that traffic generally crawls through Manhattan makes the walking environment even better. The faster multiple lanes of traffic are whizzing by, the more of a barrier you need between pedestrians and the roadway. And you're almost never walking by acres of parking - real estate in Manhattan is simply too valuable for that. Nor are buildings set back so far that they divorce themselves from the streetscape.
There are numerous destinations within walking distance, and a robust public transit system to get countless other places. Many new buildings are required to have public space within them, offering yet more potential destinations.
Oh, and I doubt zoning rules in Manhattan allow for hotels to co-opt the sidewalk for valet-parking purposes.
If you haven't heard, there's a controversy brewing over hotel plans at 500 Atlantic Avenue in Boston, where developers plan to break up the sidewalk along the post-Big-Dig Greenway in order to allow drive-up valet parking. UGH. The advocacy group WalkBoston has been involved in trying to get the plans reconsidered, supported by an editorial in the Boston Globe:
The Rose Kennedy Greenway above the Central Artery tunnel will never live up to its promise as a promenade and pedestrian connector between downtown and the harbor if its design does not invite walkers. Making sure it does has been a goal of state, city, and community group planners from the beginning. That is why it is so disappointing that the city has gone along with a hotel's request for a parking pullout at its entrance that would force pedestrians to detour around idling cars and under the building's portico as they make their way on Atlantic Avenue.
There's an extremely easy solution to this issue, which you can see at the Hilton hotel on 53rd Street and Sixth Avenue in New York -- two parallel sidewalks, one for the pedestrians walking down 6th Ave., and another for those getting out of taxis or private cars. I'll try to see if I can get a photo of it sometime before I head out.