system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why is the "passive voice" looked down upon in writing?

Every time I write a paper using Microsoft Word, it makes a point to underline any time you use the "passive voice" -- yet there is no suggestion, and reading about why it is frowned on, I don't understand why that would be.

Is there some quality about it that is hated, and why?

edit: Thanks for the answers, everyone. I think I understand it now.
gpt
Passive voice isn't inherently *bad*. There are times when it can be really clever and useful, but you have to know what you're doing. More often, it can obfuscate your meaning, and that's not good for readers, because they have to work harder to understand what you wrote. 

We typically talk about people 'doing things' (e.g.: Paul threw the ball). This takes the structure of "subject, verb, object". This is active voice. Passive voice swaps it around (e.g.: The ball was thrown by Paul). Sure, it still means the same thing, but that's not how we naturally think about the world, and so it takes more time to process.

Microsoft Word is simply flagging these instances for your review, so that you don't fall into a trap. It's not trying to say "you're a horrible writer and you need to change this immediately".