Ridership vs Coverage - There *is* a difference...

Jarrett Walker makes the point that public-transit decisions are not made in a vacuum, that there are actual tradeoffs that need to be made between Ridership and Coverage.

If public transit agencies were charged exclusively with maximizing their ridership, and all the green benefits that follow from that, they could move their empty buses to run in places where they’d be full.  Every competent transit planner knows how to do this.  Just abandon all service in low-density areas, typically outer suburbs, and shift all these resources to run even more frequent and attractive service where densities are high, such as inner cities.  In lower-density areas, you’d run only narrowly tailored services for brief surges of demand, such as trips to schools at bell-times and commuter express runs from suburban Park-and-Rides to downtown

Mind you, this goes dead against the idea of Coverage - if you told the people who were squawking about "empty trains and buses" that services to the suburbs would (and should!) be cut, then lords, would there be an uproar! Because...equity!
For example, if you looked at Seattle,

a ridership-maximizing service plan would probably offer no all-day transit service outside the City of Seattle except for links to the densest suburban centers such as downtown Bellevue and perhaps some older, denser inner-ring suburbs such as Renton and Burien.  Beyond that, the suburbs would have nothing but school services and express buses to Seattle at rush-hour.  In the dense urban fabric of Seattle, on the other hand, you’d have buses or streetcars every three minutes on every major street, with lots of rapid-bus overlays, etc, etc. 

The outcry would be tremendous, the politics toxic, the prospects for implementation zero.  I would never propose it.  But there’s no question that such a service change would dramatically increase ridership, dramatically reduce the number of empty buses...

The bottom line here is that most opponents of public-transit, through either incompetence or malice, fuzz the issues of Ridership and Coverage when it comes to measuring effectiveness

Ridership services are justified by how many people ride them.  Coverage services are justified by how badly people need them, or because certain suburbs feel they deserve them, but not based on how many people ride.