twotex,
What a great question!
Certainly there are going be generalities. Which do and do not apply to specific programs will vary.
Our experience is the end result is a reflection of a dynamic involving the views and actions of the Administration, admissions, the ability and influence of the AD and baseball coach, and, finally, the performance of the student athlete in the classroom first and on the baseball diamond second, as a reflection of the University/College. At times it might, to some extent, involve the conference affiliation, also. The new SAA breaking away from the SCAC and the College president who was leader of the break away could be an illustration.
I don't think the AD can be underestimated here in any way. They are the liason to the Administration for budget, budget responsibility and creating the view/window through which athletics can be seen and measured by the Administration and Board of Trustees.
In addition, they are hiring anywhere from 14 coaches at some schools to upwards of 35 or so at a few. The ability of the AD to select, support, oversee and foster good coaching is not an accident, I don't believe. It is a remarkable skill.
Using Stanford at the DI level as great illustration, they hired Bob Bowlsby from Iowa. Bowlsby hired Harbaugh in football from the nonDI/non BCS University of San Diego, a move many questioned. That choice turned the Pac10/12 floundering program into a National power.
The same happens at DIII's. AD's at DIII's make those types of decisions all the time but on a less public scale. The ability of an AD to sift through the massive list of candidates who will apply for most any DIII baseball job and select the right coach to be successful is a skill and talent not to be underestimated. Appreciating good choices are not always made isn't hard. It is a very real fact in college baseball at any level. As a parent, knowing or realizing a less than optimal hiring choice was made is not easy, for sure.
Take a look at the history of Trinity University, as I know it is a school with which you are familiar.. Their DIII program was floundering in mediocrity through the early to mid 1990's. At that point, Bob King was hired as the AD, and brought a model premised on Emory University. He has made remarkable coaching hires in all 18 sports and done that over and over again.
In some aspects, tradition can be added in either direction. At a program like Marietta, wearing that jersey is carrying a tradition and the responsibility of winning. At other programs, losing becomes a habit and the mind set of everyone involved becomes a reflection.
When all is said and done, however, I think the "causes" are fundamentally rooted in the Administration, AD and admissions. For those which view student athletes as a positive aspect/reflection of their college/University, and the students graduate, do well in the classroom and on the field, sports like baseball can be successful, if the right decisions are made on personnel.
Where those at the top don't perform well, view performance on the field with indifference or, sometimes, disdain, or players don't perform well in the classroom, graduate, or do what is needed to be a positive reflection of the baseball opportunity provided, those factors can be among the "causes" of a weak program.