<rant>
Disclaimer: This is about spoilers in answers. I am not saying anything about spoilers in questions.
TL;DR: I am strongly for spoilers in answers and strongly against not using them.
Why is not posting spoilers bad?
Except when the answer clearly does not spoil anything at all, not adding spoilers is disrespectful to those who do not want to read already existing answers, IMHO.
The "Post Your Answer" button is at the bottom of the page! so there is no way to post an answer without scrolling. This makes claims like "just do not scroll your page" invalid. (And the first answer might show up on the screen anyway if the question is short enough.) Further, the first answer is the one with the most upvotes, so it probably has the answer or at least a big part of it.
Spoilers serve to not reveal information that would make a a puzzle frustrating. If you see that, there is no way to unsee it. I do not have a MIB neuralizer!
What about previously defined policies?
Some people will cite badp's policy about spoilers:
This is not a network policy, but it's my policy.
- Your question must make sense without spoiler protected paragraphs. If the spoiler is the whole point of your question, don't spoiler protect it.
- Your answer must make sense without spoiler protected paragraphs. If the spoiler is the whole point of your answer, don't spoiler protect it.
- Your title must be easy to Google for. If that means spoilery, so be it.
If there's a spoiler in the title, don't mask it.
But we have two issues here. First, as he said, this is not a network policy; it is just his own personal policy.
And second, the most important: IT HAS BEEN TAKEN OUT OF CONTEXT. This is for fiction and literature sites. So you would not read that Snape kills Dumbledore. And even if you already knew that, you might not know that he does that because Dumbledore asked him to, and he was a double-agent for Voldemort. What!? Did you not like me posting this in plaintext? Now you see the purpose of spoilers!
But if you somehow think that this could be contextualized here and become a policy on this site, lets see this answer from Anna Lear on the very same question:
Literature moderator here.
Literature SE does not yet have a formalized spoiler policy. The issue has never come up yet.
As Michael Mrozek said, there is no network-wide policy. I don't know if Literature will ever develop one, but for now common sense applies: if you are asking about something that can ruin the book for someone, mark it as a spoiler. I don't think this is gonna be a huge issue for Literature, since it should be fairly easy to avoid questions about specific books or authors if you're worried about spoilers.
Let's focus on this part:
if you are asking about something that can ruin the book for someone, mark it as a spoiler.
Again, this is out-of-context, but let's force it a bit and contextualize and adapt it to fit here. What this would turn into? Something like this:
If you are answering something that can ruin the question for someone, mark it as a spoiler.
And answering a question on this site would almost always ruin it for someone. So USE THE DAMN SPOILERS!
So, what to do?
My personal policy (and this is not meant to be taken as a site-wide policy) is this:
When I see someone:
- Not using spoilers.
- Clearly spoiling the fun, at least for me.
- Insisting on not using spoilers after being asked by some other user.
Then:
I click the f*ing1 downvote button, regardless of whether it was a good answer or not!
As I already said, I consider not using the spoiler to be a disrespect to the readers, so I will behave like this from now on.
People say that an answer with just a spoiler is useless
Useless why? Useless how? Just because you need to hover your mouse over it? This is a red-herring (and a very badly-crafted one). The answer is there and the content is there. Being useless or not does not depend on using spoilers or not, it depends on the actual contents, including the contents of the spoiler.
Or maybe it is useless because there is no way to know what the answer is about without reading the spoiler? Well, that is exactly the purpose here! The very reason that the spoilers are there is so that you do not know the answer unless you really want to! And this in no way makes the answer either more or less useful.
There is no such thing as defining usefulness as a function which does not account for spoilers. This is ridiculous!
1: It reads as freaking.
</rant>