Writers shouldn't think of adopting a genre as selling out or pleasing the market, but rather as an homage to their heroes, and a small step towards saving society: an opportunity to reinvigorate the calibre of popular fiction by writing it well.
Good advice and thoughts all around, and it's nice to see more folks coming out of the woodwork and saying something that's been unjustly ignored or snubbed for too long: genres are not evil.
Genres are not evil, but they're not holy either. They're starting points. They give you a base from which to build, a handy way to let a broad swath of readers know up front what kind of story you're going to tell (the human impulse to slot things into categories is not going away any time soon, folks), and — this part gets overlooked a lot — a set of constraints which you can learn to master and then creatively break.
When I first read Gravity's Rainbow, it was proffered to me under the general heading of "literary fiction". It could have been (and often is) science fiction; it could have been a historical novel about WWII; it could have been a military thriller; it could have been surrealism. Check "all of the above", though, and an odd thing happens: your prospective market for the book dwindles instead of expanding.
There's an apparent paradox here, but it's worth thinking about. The more open-ended and inclusive your description of something is, the harder it is for people to know what you really mean. (I'm reminded of the Shel Silverstein poem where someone tries to describe the color of their eyes and ends up running through the whole of the spectrum.) It's easier for people to make one solid comparison, or maybe two, then five or more.
This is why movie pitches are often framed as in terms like "Casablanca meets Lethal Weapon" (er, yecch). Right there you have two major points of reference you can draw on. Sometimes you only need one, and from there you can build a fairly good idea of what to expect. People need at least some hint of what they're getting themselves into when they start reading a book or watching a movie.
The other week I finished reading, and am still trying to figure out, Epitaph of a Small Winner. I love the sheer unclassifiability of the book, but I know that is precisely the kind of thing that will send most people screaming from it into the comfort of the latest Janet Evanovitch comedy-thriller. (See what I did there? With two words you know exactly what Stephanie Plum is all about.)
Sure, Small Winner is "literary", but if I'm going to talk about it in a way that will attract more than, oh, the six people that read this blog, I need to find a better way to do it than to say "just read it and find out for yourself". This is a cop-out, a tacit admission that you haven't really thought about the work or how to get people to connect with it.
Too much of the truly ambitious and "serious" writing produced since the early years of the 20th century falls into this trap. It forces the reader to approach it on its own terms, but in doing so ends up divorced from any kind of real tradition of reading. The end result is a lot of books that all want to be #1 in a category of one, or which disavow that accepting influences and building on existing traditions is a good way to, you know, tell a story.
None of this bothered Georges Simenon when he wrote his — literally — hundreds of novels, some of them among the finest produced in the last century (we're still getting caught up with him, it seems). He wrote books that we would call psychological thrillers, and I don't think he would have been upset with the label. If it gave that many more people an excuse to pick up his work and get to know it, how is that anything other than a sensible strategic advantage?
The project I've recently started, Flight of the Vajra, is unabashedly far-future space-opera -style science fiction. I have no problems calling it that. But I know that I've got a responsibility to both live up to and transcend that label, each in their own measure.