Otherwise, either you have to cut yourself off from all media and conversation that might possibly reference the movie, or try and convince everyone you might interact with, and everyone who might write anything online, not to discuss the movie. Neither option seems particularly pleasant nor realistic to achieve. I suppose you could also just see every movie you intend to see on the first showing of the opening day.
What you are doing by asking for absolutely no information at all, even the basic exposition and setup of characters at the beginning of the movie, is imposing a large burden on everyone else around you to prevent a very minor inconvenience to yourself. I understand not wanting major spoilers, and that there should be a reasonable time before discussing those points openly without a spoiler warning. But it just seems that the trade-off is fairly poor for not even allowing the most basic discussion.
But that does not mean there is not still a lot of stuff that really should be considered spoilers, and the complaints about these should not be brushed off just because you think I expect you to not mention anything about a movie. I think it's a very valid criticism when the article in question reveals something that even the trailers kept unknown by never showing that person, without any need for it in the context of the article. It's like saying "The Sixth Sense, where he was dead all along, was quite good, I loved the cinematography." a week after that movie was released. While I personally would not have wanted to know about the cinematographical quality either, I realize I can't complain about hearing something like that when reading a review or when I'm not fleeing a discussion of the movie quickly enough. I never would complain about that. But I'm sure I'm not the only one who would be pretty annoyed to read said plot detail in an article about e.g. "The decline of quality in M. Night Shyamalan movies" a week after that movies release.
To sum it up: I agree with your basic point, but I think too often people that are fine with spoilers don't care about the fact that other people have a different level of acceptance and when confronted with that simply resort to saying "Well, it's silly to have this level of acceptance."
I actually managed this pretty much with the new Star Wars movie - but then on the way in to find the screen was greeted with a massive poster showing lots of info about the movie. I averted my eyes. Then at the entrance there were sales staff touting character drink cups which successfully spoiled a couple of the characters who would feature heavily.
After the movie I watched a BBC program which supposedly reviewed the Star Wars franchise and promised no spoilers. Pretty much the entire plot and many of the scenes could be determined from the content they gave.
The problem I have nowadays is that trailers seem to include the entire plot, all major characters, all the best effects, all the most emotive scenes; ostensibly the entire movie in digest. These to me are very poor trailers.
Generally I agree with your points however, lambda.