@apu It is and isn't. I mean on here, the movies talk, I go and look at unread posts and see the first few sentences of the latest Good or new movies thread. (as an example, not complaining!) but there are no spoiler tags and it's pretty darn spoilery to what's going on. it doesn't outright say the spoiler, but if you know the characters and what's going on, it's something I didn't know.)
Sure this is a minor-ish spoiler, I guess, because it's been spoiled all over the internet, not who but what, but it's not small.
So there are people who will purposefully do it, but people who casually spoil things as well.
Spoiling is just part of being on the internet, is what I'm saying, and either people will be dicks about it, or not. But even when people aren't the potential to be spoiled is there.