Which is the exact type of things that leads to customer complaints. Customers have to be inconvenienced in order to do maintenance on the NYC Subway. In turn the bar to require maintenance will be higher than it is in London. The natural result of years of delayed maintenance is for the system to get worse and worse as time goes on.
I disagree that maintenance is more difficult in London than in New York. I spent about two weeks in London about a decade ago. The first thing that struck me is that when you arrived at the tube station in Heathrow you'd get all sorts of information about which lines were in service that day. In trying to navigate London there was a constant shuffle about which stations or lines were out of service. Plus it took about two hours to get from Heathrow to Victoria due to signal issues (the wrong kind of snow is also an issue, apparently).
