As I said in my response to Philip Hensher's diatribe, the mystery genre being "rule-bound" doesn't mean it is necessarily adverse to originality and innovation. Shakespeare, Spenser, Wordsworth and Auden all wrote sonnets and it doesn't seem to have hindered their creativity nor their individuality. But there was no one around to tell them what their themes should be or which language they should use; as long as they played by the rules (or didn't subvert them too openly) and didn't write anything too outrageous or offensive, they were free to do as they pleased.
Mystery writers on the other hand are repeatedly told - and most often agree - that their genre of election is realistic by definition* and that its sacro-sanct mission is to "explore the dark side of human nature" or "comment on the grimmy aspects of society" or both. They are also strongly advised to write in a straightforward manner, one that avoids anything too recherché or obscure. It is not my intention to belittle this approach to mystery writing: some outstanding work has been and is still written according to those guidelines. But turning them into "articles of the faith" I think is detrimental to the genre's vitality. We should see mystery first as a form, one that allows and calls for many uses and interpretations. If X wants to use mystery to explore the human psyche and comment on society, that's fine. But if Y is more into genre-bending or narrative experimentation or "just" fair-play plotting, that's fine too. We must make the tent bigger and more welcoming. Above all, we must no longer be afraid of the "I" word. Then and only then we'll have our own China Miéville to show the Henshers of the world.
*Which is at best debatable, but it's not the subject of this post.