It's not that so much, grammaticaly speaking, as the idea of putting the object first in the sentence for clarity. A different sentence structure would feature the writer or the scientists and technicians, which would put the main attention on the scientist rather than the science. Featuring the actor rather than the object might be appropriate for a politician, but science requires an impersonal mode.
The student of rhetoric will also tell you that the passive voice deflects more than just immodesty. It functions as an oblique way for the reader to slide over what might otherwise prove uncomfortable for the writer--asking "who came up with that 200M or 700M figure--kind of outlandish, don't you think"? There's a heap of "surmisin'" that slips by with the use of the passive voice.
Science is influenced by nuance.