Some places can build infrastructure; others can't. But then some places want and others don't, and it's not in perfect correlation.

Can't, doesn't want to: New York, most of the US in general.
Can't but wants to: Los Angeles, Toronto, UK - look how hard they try to build those few lines.
Can, wants to: France, Spain, China, many others.
Can but doesn't want to: Germany, to some extent also Japan - this is seen in low costs per rider, i.e. lots of good value left on the table.