I learned in a grad school composition class that the passive is fundamentally ok and isn't the bogeyman that our high school teachers say it is. Rather, it can help make your writing significantly clearer (I'm surely not the only person who's ever rewritten a sentence into grammatically gnarly mess just to avoid the passive), especially if we keep one specific compositional guideline in mind: that the main topic/idea you're talking about should, as often as possible, be the subject of your sentences, because that subject position is a privileged position. You can think of them as the anchor of our attention, that they orient our thinking. (You don't want, then, to have too many different subjects, just as too many anchors on a ship will drag it down.) This guideline has a lot more nuances, but for the sake of brevity, this description will do.
For instance, if you're writing an article or paper or book about Abraham Lincoln -- Lincoln debated Douglas, Lincoln became President, Lincoln freed the slaves, Lincoln saved the Union, etc. -- which of the following sentences would, from a compositional perspective, make more sense?
Lincoln was assassinated by John Wilkes Booth.or
John Wilkes Booth assassinated Lincoln.
I would say the first sentence, even though rewriting to avoid the passive in this case is trivially easy. My reasoning: you've been talking about Lincoln all this time, he's the center of your piece, and all of a sudden you introduce this new character -- John Wilkes Booth -- which momentarily surprises the reader. A single, isolated example won't turn your writing into mud, but if you keep surprising your reader with a constantly growing cast of new characters/concepts, then the reader is going to get tired or confused because you're making them do more of the work that, honestly, you should be doing.
Indie rating: KaitO - "Try Me Out"