Oh, $deity$.... now I'm sorry I opened up this Pandora's Box in the first place by talking about plagiarism!
raisindot, I politely disagree with your statement that all fan-fiction is creatively bankrupt rubbish. However, I
do agree that kids don't get taught to question what they read and think critically about it. So when someone writes dreck like
Twilight, or ($deity$ help us)
Fifty Shades - and it actually becomes
successful - then it encourages wannabe writers to imitate it in the hope of making a quick buck, usually with disastrous results on the creative front.
Having said that, although a lot of fan-fiction these days is creative rubbish, not
all of it is.
Quartermass, I agree with you that not all fan-fic is trash. If writing it makes you happy, then that's all that should matter!
This whole discussion inspired me to think about this decline in critical thinking. 20 years ago, I wrote fanfiction myself (based on Sierra's classic RPG adventure,
Quest for Glory), and published it on several forums, including Sierra's official forum. Fan-fiction was permitted by Sierra, with the usual clause that it was not to be published for money. We were all, naturally, happy to oblige and accept this compromise.
Many things have happened since those simple days of dial-up. Faster and more accessible speeds, more and cheaper bandwidth, far more content than ever before. But this rise has not been accompanied,
generally speaking, by teaching kids to take responsibility for actions, to make compromises, to think about how their actions affect other people. Instead, it's just a simple philosophy: "I WANNIT, IT'S MINE! GIMME DAT, IT'S MINE!!" I'm not saying that all kids are brats like that, but some are - and unfortunately, many adults are too. (Just look at a certain candidate for the US Presidency, for one. "I ALWAYS WIN! I NEVER LOSE!" etc.)
This is probably one reason, at least, as to why so much fan-fiction is such drivel. Wannabe writers want to make a quick buck without putting in the hard yards - it's as simple as that. Add to that the above attitude - e.g. "That character is cool! I'll use him" - and you end up with the Harry Potter knock-offs I mentioned earlier.
These days, I mostly write rigorously researched (but light-hearted) historical fiction. However, I certainly hope that no-one will accuse me of plagiarism if I write about (say) Owain Glyndŵr, Genghis Khan or Ivan the Terrible.