A number of reasons already discussed, but in person it has the “benefit” of slowing down (drawing out) bad news. It’s like string betting in poker, but it’s also a way of showing dominion over time (by burying the lede and making someone anxious.)

Passive voice is a tool. It’s perfectly valid and grammatical. The problem is the abuse of it to misrepresent one’s agency or responsibility, but there’s nothing wrong with the sentence, “I was hit by a car on the way to work.”

The issue with corporate passive is that business language is not only ugly but serves evil purposes. In person, it exists to slow down bad news so you can read and manipulate people (“string betting”) and, on paper, its raison d’etre is to project authority to which one has no actual right.