My teachers hammered "Thou shalt not use passive voice!" into me from middle school on up to college level creative writing classes. Even on academic papers some of my science teachers would insist on writing lab reports by saying something ridiculous like: The experimentor applied the following forumula to achieve maximum density. That, rather than: The following formula was applied to achieve maximum density. All for the sake of avoiding passive voice! It got to be pretty silly in my opinion.
Passive does have its uses, though I tend to believe they are usually stylistic. For instance, one can use passive to de-emphasize the doer in favor of the receiver of an action. The problem I have with passive arises when someone uses it too frequently, or sacrifices clarity as a result.
