1. Fantasy is for children.
If, by this sweeping claim, you mean fantasy is a form of juvenile wish-fulfilment then I would respectfully point you to the many hardships, moral dilemmas and deep-rooted personal questions that fantasy characters typically have to face. Anyone who actually wants to live inside a fantasy novel must really enjoy confronting their worst fears. No, there are far worse offenders around when it comes to unrealistic daydreaming (cheap romance, anyone?).
If you mean fantasy can recapture some of the wonder, excitement and sense of adventure that we only have when we're children, whilst at the same time confronting the fundamental questions that most 'adult' fiction seems to shy away from, then yes. Fantasy is for children – or at least, anyone who was once a child.
2. Is that why it's so easy to write?
I have no idea whether fantasy is easier to write than any other genre. It's certainly no easier to write well.
This misconception may come from the fact that there are an awful lot of would-be fantasy authors around – more, perhaps, than the market can take. But concluding this means fantasy is easy to write is like using the existence of the X Factor to prove that it's easy to be a musician.
3. Well, ok, but it's not really literature, is it?
No, for a certain narrow definition of literature. But nor is crime, thriller, historical fiction, chick-lit or anything else that can be categorised by genre. So it's not like fantasy really loses out on that score.
For a more sensible definition of literature, yes, fantasy can be as beautifully and cleverly written as anything else. But like any other genre, there are literary fantasises and commercial fantasies; language-focused narratives and action-focused narratives. Exactly where a book falls between these poles is up to the individual author, not some mysterious set of genre guidelines.
4. I'm just not into elves and orcs and stuff.
Great! Nor are many (most?) fantasy authors.
The wonderful thing about fantasy is its breadth and depth. Sure, there are Tolkien clones out there, but there are also numerous unique and fascinating worlds just waiting to be discovered. One of them is sure to suit your taste, whether you like your magic flashy, gut-wrenching or non-existent.
Fantasy may have been heavily influenced by Tolkien, but it didn't end there. Nor, if you're interested, did music end with the Beatles.
5. But it isn't real.
It's as real as love. It's as real as courage, despair, freedom, hope and friendship.
If you answered 'but those things aren't real either' then I suggest you go and read a book about dry rot or something equally tangible, and leave fiction to those of us who still believe in life.
'Lock the doors, stop the clocks, switch off the internet' – @HMGoodchild
The interweb is a wonderful thing. But it's also a distraction and a massive time-waster.
If possible, I really would recommend writing on a computer without an internet connection, or even (if you like things old school) a notebook. The non-electronic kind. And if, like me, you have a partner with an iDevice then ask him/her to hide it somewhere you'll never, ever find it.
Of course, this doesn't apply to genuine research. But just so you know, spending hours on TV Tropes isn't research. Especially if you're not writing anything down.