If I was going to be super-cynical, I'd suggest writing a book that is 75% Tried and Tested and 25% Wacky and New. But then I think that really is way too much like writing by numbers and definitely not the right approach.
As far as reading in the genre is concerned, I think we're discussing degree here rather than yes or no. What I would say is that you're not going to learn much from reading older books only. I actually have a lot of nostalgia for old fantasy, partly from the Eddings era and partly from games like Baldur's Gate: the weird mix of medieval knights, Victorian houses and pioneer farmsteads; the straight-up adventure; the fact it's always sunny except in Winterland. But that's just not what I'm wired to write. One thing that struck me while reading The First Law - which is very good indeed, although not the work of flawless brilliance sometimes suggested - was that that a quite lot of fantasy novels either repeat, comment on or satirise what people think of as "classic fantasy" (which means Eddings as much as Tolkien). I'm not sure what to make of that. Should the genre just move on? Does the current generation of readers want it to?
To an extent, the genre has moved on. There's less timeless pastiches and more faithfulness to particular periods of history. Less medieval and more renaissance (with a creep towards the Age of Enlightenment). Less 'well most people are nice' idealism and more probing at the skeletons in the closet. Less superheroes moving the world alone and more struggling over the command of large organisations.
The First Law was a classic fantasy trilogy given a big make over after Abercrombie read
A Song of Ice and Fire, which is probably the dominant influence at the moment.
To the extent the genre hasn't moved on and is still probing at different takes at classic fantasy, why should it? We're all here because we love the concepts behind it, if we just don't flat out have a lot of love for it. How many genres do move on?
On a slightly different note, I'm not sure that my dislike of teenageryness in novels is cynicism. If someone is entitled to wish that there were more dynamic female characters in fantasy, surely it's equally reasonable to wish for more protagonists who start the story "fully grown"? It's less of a politicised point, but I think an equally legitimate one in terms of what you want to read about. One thing that a book does seem to lose from having older characters, though, is that it feels slightly more dour and joyless. There's a certain enthusiasm that it's harder to get into characters who aren't very youthful.
At the risk of misrepresenting Brian, I think he wasn't accusing you of cynicism for disliking teenagers, but saying you needed to put aside your cynicism about the genre's quality and dig deeper, regardless of whether it contains elements you dislike.
Have to say I've never really thought of older characters as being less joyful. But then people talk about getting a sense of wonder from books and I'm there scratching my head.
I'd also add the more modern you get in the genre, the more the age profile varies and the older characters are in general. In fact, the more I think about what I've read of your posts, the more I'm wondering what Epic Fantasy you've been reading because it doesn't feel that representative of what I'm seeing.
I agree with you, Peat.
I personally don't ascribe to the "read recent fiction to understand the market" myself. For the same reasons I say don't watch the latest movies to know how to make them. There's an inherent flaw in that logic. Namely: if what you aspire to is what you read, you can never achieve greater than that.
Surely the answer here is simple - don't aspire to all you read. Aspire to the best, study the rest.
I'm not sure how I feel about the whole "comprehensively understand your genre" thing myself. I've tried doing it and I'm not yet clear as to what extent its benefited me. But I am fairly clear that is hasn't changed my aspirations at all.
On the subject of reading for study/investment, I do think its worth reading the mid-listers (particularly recent) as well as the greats.
The first reason is they are a better source of genre conventions than the greats.
The second is that no author does every single piece of their craft to the same level and that means that, even in a book which is fairly 'meh', there's still often something brilliant to look at. Peter Morwood's
The Horse Lord has been mostly forgotten and that's because it didn't offer much that was brilliant but it did do a good job of making an arrogant young warrior with a hair trigger propensity for violence (by modern standards) likeable. That's not always easy.
I'll admit I've taken away very little from my forays into recently published Epic Fantasy. Miles Cameron does a nice job of interweaving the fantastic with a fairly hard realism late medieval setting but that's about it (worth looking at if you want to mess around with multiple PoVs a lot too I guess). But its very much YMMV.