One of the examples mentioned in that article is that with classical tragedies, it's more enjoyable to know the ending beforehand, so you can appreciate the inexorable movement towards it better. Which I agree with, I guess - if you read, say, Antigone expecting everything to work out in the end, you will not only be likely to miss the full weight of some events or words, but you'll also be disappointed and annoyed at the ending. Though to be honest with most tragedies you'd have to be a bit obtuse to not see the tragedy coming even if you don't know the ending yet... anyway.

For most other kinds of stories, I don't really see the argument working, though it will depend on the reader of course. But for the kind of book that really has big plot twists that can be "spoiled", I think finding out about it beforehand will almost inevitably make the reading experience less emotional - you don't go along as much with the story in whatever direction it's going, because you know there'll be a twist and it'll end up in a different direction in the end. In some cases, there's no doubt that the emotions you're spared that way are negative ones - disappointment, sadness, anger, revulsion. And that might of course make someone like a book better.

I recently reviewed Lionel Shriver's book We Need To Talk About Kevin. A book in which the main element of the plot is clear from the start even though it's only described in detail near the end; but the ending chapters of the book contain two secondary plot twists that hit hard indeed, and leave the reader feeling rather conflicted at the end of the book (at least that's the effect they had on me). If those two twists were spoiled from the start, I guess one could argue the psychological depth of the characters would be enhanced, and the reader could watch out for indications of what was to come (this is of course assuming that the book or story is sufficiently well-written as to hold up to such closer scrutiny - in novels that's probably the case most of the time, but in TV or movies, I dare say it sometimes isn't). The reader would also be saved a nasty shock. But they'd have a less emotional, less spectacular reading experience. I guess it's a matter of preference, but imho most people like to get caught up in a book, and so want to read books unspoiled if they have the choice, rather than the more analytical, detached reading you do when you already know the big plot twists. At least the first time. You can always do the analytical reading on your re-read.