disliking spoilers is an inherently childish trait
This is 100% a childish trait when you have full control over what you view. Deliberately spoiling yourself with content you haven't watched then having a tantrum about it is kid behavior.
Don't want spoilers? Click that [x] button in the upper right and watch the fucking media FIRST. Especially if it's old media that's been out for years and years.
You lose the right to complain about spoilers in these cases:
1. The movie has left theaters
2. The season has ended
3. The book/manga/comic has been out and released for half a year or more (which is GENEROUS by the other standards).
If you haven't read/watched that shit immediately, you don't care enough to get the right to bitch about spoilers. I'm fine with giving people some time to watch shit around work/life, but the fact of the matter is - you don't care if you don't consume the content fast.
And really, spoilers only affect "twist" endings where knowing changes how you watch. You aren't ruining a romcom by saying "will they won't they" or "they do"/"they don't". In fact, knowing a media item results in "they do" makes me more likely to watch, not less.
tldr: bitching online makes you a little bitch.