I was listening to a podcast this morning and the person was talking about NIH Syndrome. This is one of those things that consistently rubs me the wrong way, primarily because I believe that managers' actions and managers' talk diverge significantly in this area. Many things that are not invented here cost money. Because, as a coworker once put it, "man-hours are free", the tendency for a lot of managers is to use their people to re-invent the wheel rather than putting together whatever justification the organizational bureaucracy needs to cut a PO. Since people are now re-inventing the wheel, to satisfy their ego they must be able to do it better. Do this enough times, and it's clear that NIH really is the symptom of poorly performing management.
Of course, person-hours are not free, rather they've already been negotiated for, while budgeting extra dollars for outside products or services often involves more administrative work. It's the management path of least resistance.