I personally had zero expectations that a blog post around the subject of spoilers wouldn't talk about spoilers. So, not ironic for me.
Just like I expect that visiting a web page about how frustrating malware is would infect my computer with malware.
Poor analogy imo. It's socially acceptable to talk about movies that were aired years ago with or without a warning. It's never socially acceptable to infect someones computer with malware prior to explicit consent. There's an expectation that someone writing about spoilers, will in fact detail the spoiler in question. Given that's an expectation you consent to being told about the spoiler by reading the article. If that isn't an expectation, I'm curious what you or anyone else had hoped the article would be talking about?
It's very vague about the other movies, I disagree.
Even for the subject of the post the only spoiler is the single word "chestburster".
The issue is statistics. There are billions of blog posts and only a tiny fraction of them talk about content of story based media, and most of the ones which do so are prefacing spoilers or hiding them. Same on forums.
On the other hand 99% of all cinemas show spoilers of various severity before 99% of all movies. I've stopped watching movie trailers on streaming services a decade ago and the issue was severe even back then. Cinemas show the same or even longer trailers with spoilers for practically every movie in current season. It is rather offensive for me - to pay money to watch movie and get worse experience than pirates have.
I was careful to word it in such a way that I would NOT spoil the movies I discuss.
"chestburster scene" isn't a particularly hard one to figure out
The article isn't saying "don't talk about these old movies at all as it spoils them"; it is, instead, very explicit that this is about "the movie we are seated to see".
How many kids are reading it though?
And further, would a kid want to be surprised by the spoilers contained in the entry?