Perhaps because New York's Subway is much older? It's more than a 100 years old, and has been remarkably resilient through the decades. Of course it has many problems as already pointed out in this discussion thread, but it's an engineering marvel in an of itself when it was built, given the constraints.
The London Underground opened over 150 years ago, and yet manages to keep up with capacity requirements, open new lines, and generally is incredibly reliable. I'd be surprised to get to a platform and wait longer than five minutes for the next train.
Part of that is because they don't run 24 hours allowing maintenance to take place at night, but I think the biggest factor is Transport for London being a mostly independent entity - they're not required to put money they make back into a central pool, and instead can reinvest it in their own services.
I couldn't agree more regarding MTA vs. London Tube! The tube has slightly less passengers/year and fewer stations overall, but it provides a much better user experience despite being older and with greater engineering constraints (the deepest tracks are 60m below ground) [1].
WiFi is already in virtually all stations since years.
> Part of that is because they don't run 24 hours allowing maintenance to take place at night
This has changed with five lines now operating 24/7 [2].
Night service is currently only running on Friday and Saturday nights, although if I remember correctly that's due to a dispute with the driver's union, rather than TfL wanting to have some nights for maintenance.
My understanding is that the "weekend only" is just a first phase, and they will extend the service 7 days a week during the course of 2016. Assuming they find an agreement with the Unions, I guess...
It shouldn't all be older, though - in the time that most of the Asian metros have been built, we've built, uh, the F train tunnel and a 7 train stop in the middle of nowhere? Really?
London has an even older system, with more constraints (it was built with two tracks, not for). Yet they are doing the right scale of investment: new lines costing billions.
