I'm no fan of Robert Moses but you'd have to be delusional to think any city administration could've expanded mass transit during that time.

You have to understand that Robert Moses was a special kind of asshole who despite the controversy still got shit done. He ruthlessly abused city and state powers , colluded with contractors , and ofcourse manipulated public opinion. Master builder isn't a term handed out easily yes he was an absolute tool but he did something few others could pull off in NYC of all places.