Introductory over-exuberance

This week I've been reading a collection of short stories which, due to the weighty publisher, has something of an academic overtone. The selection seems to have been made with a view to representative features, and of course there's a ponderous introduction. Like most ponderous introductions to Literature it seems to assume the reader is either already familiar with the contents or is reading the book for scholarly reasons, and it has no qualms about discussing twists or endings. OneMonkey ceased to read introductions of any sort a few years ago: I gave him a book he had not even a passing familiarity with and he began, logically enough, with the introduction in which it said 'when Main Character dies towards the end of the penultimate chapter...'. Foolishly, I continue to read introductions, stopping hurriedly if it seems about to give something away, then returning to it once I've finished the story itself. It can be interesting, even useful, to give a little context, suggest related works or compare themes with other novels, but I wish the editors would use footnotes where necessary, then a discussion afterwards when they can be confident they won't spoil anyone's enjoyment.