The active voice forces one to be specific and confident, not wimpy. And the stakes can be higher when you're talking about atrocities worse than bad papers. It should make you shudder. In your own writing, therefore, try to prefer the active voice whenever you can. Don't go overboard, though.
Some passives are necessary and useful.
Even in non-scientific writing, not all passives can be avoided. Don't confuse am , is , are , to be , and such with the passive voice, and don't confuse action verbs with the active voice . The real question is whether the subject of the sentence is doing anything, or having something done to it. I have been giving is active, while I have been given is passive. Avoid the businessese habit of using per instead of according to , as in per manufacturers' guidelines .