"FUD", for short.
The term "Fear, Uncertainty, and Doubt" was apparently coined by GeneAmdahl who supposedly used it when describing a tactic used by the InternationalBusinessMachines salesforce to cause potential customers of Gene's new company, AmdahlCorporation?, to think again about buying products from any company but IBM.
More generally: 1. The tendency of human beings to let negative emotions such as fear, uncertainty, and doubt constrain their choices and decisions, which might otherwise be based on a more rational or pragmatic basis. 2. A marketing strategy to get consumers to choose a particular brand (or, more often, pass up a competing brand), or purchase a good or service they might not actually need, using the emotional factors discussed in definition 1.
Today it is often applied to MicroSoft (especially with regard to their recent comments about OpenSource being akin to cancer). MicroSoft has been using FUD successfully for at least ~10 years ago, e.g. DR-DOS and Windows compatibility.
Thirty years ago no-one ever got sacked for buying IBM. Today, substitute Microsoft. Tomorrow: who knows?
"FUD" can be an effective tactic a "market leader" can use to discourage customers from going to the competitors: The more fear, uncertainty or doubt a person has, the more likely they'll want to "go with the safe bet" -- the market leader.
ProfessionalPerfectionism is a different, but possibly related concept.
The human trait that empowers FearUncertaintyAndDoubt is the probably the same one that empowers AdVerecundiam and QuotingNotThinking.
See also WarmFuzzyFeeling