I'm not Dan's biggest defender, but I doubt you could replace him with anyone else and expect substantially better results. A much larger housecleaning would need to take place from the top down to really bring about much of an improvement.

Frequently horrible service, station renovations which have in some cases taken longer than it took to build the entire central subway, and expansion plans that favor projects receiving the least amount of public support being forced through... it all points to what is essentially a broken organizational structure and layers upon layers of bad management.