Speaking as someone who has discovered himself to be attempting to be an author (after attempting to be a cartoonist), the obvious derivations from timeless literature, folklore and history are VERY convenient.
-
If an writer can get your brain to identify an obvious stereotype, they have just saved themselves 2 chapters of boring exposition to explain the temperament, religion etc of an individual or race.
In GW's case, it may not be so much lazy as clever.
If you can identify yourself on the following table, you might buy the book and the army:
Monty python and holy grail fan - Bretonnia
Ruthless Pillager and Glory Seeker - WoC
Arrogant Elitist - High Elves
Sick Weirdo - Dark Elves
Just want to be left alone in your pathetic misery - Tomb Kings
Fat Bastard - Ogres
Noble, righteous and attractive, but with no comprehension of women - Lizardmen
Beer Swilling Grump - Dwarves
Scalenex - Vampire Counts
Thought you were a bad boy playing Star Wars something, but realized too late that you had bought - the Empire
Tree Hugging Hippy - Wood Elves
Militant Tree Hugging Hippy with a vengeful chainsaw - Beastmen
Think random hilarity is funny - Skaven, Orcs and Goblins
Have vestigial horns and live at 666 Hell Street, Purgatory, Colorado - Daemons of Chaos
You might buy the product for other reasons (plays well in all phases, looks cool, has dinosaurs, magic frogs are inherently awesome, easy to paint to decent standard etc) but the basic fluff / stereotype will drive you away if you can't connect with it.
HOWEVER
The flaw with GW's insidious plan is that 70% of the time, the stereotype is BETTER than their effort, and people's own imagination is better still.
THEREFORE
Stick more wings on that sucker, call it a Toruk ('Leonopteryx' [my translation = 'Looks like a lion with wings' - you tell me James Cameron isn't lazy, too]) and write yourself some special rules. Come back to the L-O forum and discuss appropriate point costing then jump on board with your little Navi pony tail (which obviously should have been your tail - extension of spinal cord etc)
Then dare your weeny High Elf so-called friends to take to the air against the "Last Shadow"
How can they argue - you are already blue, aren't you ? (unless you didn't take the GW stereotypical blue LM colour scheme....)