The first factor is that as technical information in the computer field becomes more and more popularized and voluminous, there is a tendency for decision making to be made by consulting others - be it via print or hearsay. It wasn't so in earlier days when computer knowledge came solely from personal experience. The transition from scientific knowledge that can be tested to personal opinion that is taken on faith is just the opposite of the evolution of Western culture. At one time, we thought there were Gods on Mount Olympus, that the Earth rested on the back of a giant Elephant, and that the position of the planets at birth dictated ones fate. Through observation and testing, we have determined that these beliefs are unverifiable.
Modern science validates beliefs by observation and tests that are repeatable by anyone.
If you were to ask an astrologer how he acquired his beliefs and knowledge, he would state that this information was handed down to him by tradition and sacred writings. Now approach your company's CIO, if you can, or a very senior IT manager and ask him or her how it is that they know WindowsNT is a better choice than Unix. Or ask why Windows95 is a better choice than the Macintosh. Chances are, you'll get a response that is based on a personal belief that cannot be tested. Because the structure of this person's beliefs is based principally on what they have read in the last five years in the various PC publications.