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.