I have recently taught William Golding's schoolboy classic Lord of the Flies and, on considering it, it quickly struck me why it's so popular at GCSE (exams for 16-year olds, for my non-British visitors):
1) It has slightly rude words in it. Which schoolchild doesn't get a thrill from asking their teacher to explain 'orgasm'? Ho ho ho.
2) Boys love to read about boys - far easier to identify with Piggy or Ralph (the ultimate aspiration) than with Lizzy Bennett or Dickens' Estella.
3) It's so bloody simply written that it requires absolutely no thought to examine. Is symbolism still symbolism if the author tells you what it all means? The conch, Piggy's glasses, the fire, the beast, the Lord of the Flies, the weather - Golding baldly lays out what each of them represents.
Simon the Christ-figure struck me as completely removable, either a successful attempt to show the redundancy of one particular religion or an unsuccessful one to create a moving, holy figure. The result is in fact a badly-inserted figure whose role could easily have been doled out to other characters. His sacrifice does not tell us anything about Christianity or anything that we haven't yet realised about the tribes.
His dystopian (or perhaps realistic, atavistic) world-view is brilliantly horrifying, and there is enough tension to go around, but as a text for discussion, its merits are about as few as its symbols are plenty.
Or am I just rebelling against the tyranny of text-deconstruction?