Its always a people problem

There seems to be a common underlying theme running through many software development classics (who have I missed?):

In The Secrets of Consulting Jerry Weinberg writes:

It's always a people problem.

In Peopleware Tim Lister and Tom DeMarco write:

If you find yourself concentrating on the technology rather than the sociology, you're like the vaudeville character who loses his keys on a dark street and looks for them on the adjacent street because, as he explains, "The light is better there."

In The Mythical Man Month Fred Brooks writes:

The Mythical Man Month is only incidentally about software but primarily about how people in teams make things.

In Patterns of Software Richard Gabriel writes:

My overall bias is that technology science, engineering and company organization are all secondary to the people and human concerns in the endeavor.

Notice that none of them say it's a person problem.