that they look at the first page and dont leave it to write they comment and then watch for the alert that someone quoted they post.I mean, considering the size of the game is at least 3x more than most direct download sites allow and a single part archive would barely cut into that and considering the prevalence of games of this file size now, yeah. As far as people reading, I would suggest actually going through some of this thread to see what I mean. There are even cases where the same question is asked on the exact same page or is answered right before the next guy to ask with no spoiler to hide it. If they aren't going to read from the exact same page their comment goes to, what makes you think they'll take an extra step to open a spoiler?
also the fact some of them quote that spoilered post on the frontpage and ask what it means.
after all you arent on a text document where you need to go to its bottom to write something new.
furthermore we are on page 358 and people see that its a lot of pages and dont bother.
then again we would only know if the frontpage was edited to include a proper explanation and the posts would stop.
also that spoiler as you put it has a big installation name and is in they eyes while they are downloading the parts.