On the one hand, the behavior guidelines begin as follows (bold by me):
Above all, be honest. If you see misinformation, vote it down. Add comments indicating what, specifically, is wrong. Provide better answers of your own. Last but not least, edit and improve the existing questions and answers! By doing these things, you are helping keep Stack Exchange a great place to share knowledge of our craft.
While you’re doing all of those things, we also require that you...
The privilege documentation on downvoting on the other hand reads like this:
When should I vote down?
Use your downvotes whenever you encounter an egregiously sloppy, no-effort-expended post, or an answer that is clearly and perhaps dangerously incorrect.
Down-voting should be reserved for extreme cases. It's not meant as a substitute for communication and editing.
Instead of voting down:
Why are these in contradiction to one another??!!!
The guideline suggests to always vote misinformation down, while the privilege documentation suggests that downvoting should be an action of last resort in improving a question or answer. In my experience, when a person, who subscribes to the privilege documentation's version of downvoting, gets downvoted by someone who follows the guideline's version of downvoting, there is much outrage and indignation that even spills over as abuse toward the downvoter (sometimes veiled as polite shaming of the downvoter for not being constructive, even if they do comment to explain their downvote).
My personal opinion is that the suggestion that downvoting is an action of last resort only leads to grief and aggravation because
- users do not always downvote as a last resort
- the user interface actually encourages downvoting as a first response by making it as easy as upvoting
Instead, the idea that downvotes indicate that someone thinks a question or an answer is of poor quality is, I think, an accurate and objective description of how users actually use downvoting. It does not allow, in particular, for the sentiment of "you should not have downvoted what I wrote even though what I wrote was wrong".