"Wishful Thinking" was such an absolute spoiler for this. It completely removed any potency from the twist, and a wonderful gut-punch instead became a frustrated read, devoid of any impact. I get tags are for finding things and avoiding others, but this is a bit much, I think.
Can people really not stomach reading a few pages of something that turns potentially unpleasant for them? Does everything in today's society have to have child-proofing and "rounded edges"?
Maybe the site could have an option tied to your account settings, where you can toggle "spoilery tags". So tags on certain works that would ruin an individual story can be hidden for those who don't want to be spoiled over potentially reading something that might not interest them, and not-hidden for those that simply want to avoid whatever might potentially discomfort them? (It would have to be per individual story, but it would be pretty obvious to the uploader what tags would spoil the story.)