Is writing in the literary fiction genre a futile exercise these days if one would like, some day, to have more than only those nearest and dearest as readers? Is it correct to assume that marketability – in the form of solely plot-driven, rather than character- or theme-driven manuscripts – is the primary focus of publishers in our commercial world? If my passion is to take readers on an emotional and evocative journey, to create vivid images through description and to express ideas about lives not immersed in mystery/turbulent romance/fantasy/Opus Dei and dramatic turmoil of that ilk (not that there's anything wrong with that), should I resign myself to seeing my scribblings in print only when I supply the ink, paper and technology myself?
I'm not going to lie and say that literary fiction as a 'genre' is about to become the most popular thing around. It never has been - Jane Austen certainly wasn't literary fiction in her time, and nor was Dickens (who understood marketing even before it really existed).
Part of the problem is in classifying any writing at all as 'literary fiction', because these days that implies a novel that is worthy, turgid and requiring some work by the reader. It's much better to write what you want to write and let the agent/publisher decide what it is. You should always write a good story, well told, regardless of where you think it should go in the bookshop (which is really what categories are all about - making it easier for booksellers to shelve books).
The key words in your question are 'passion', 'emotional', 'evocative' and 'vivid'. Beautiful - this is exactly what all fiction should have. So stick to these principles and you may find that not writing about Opus Dei doesn't really matter. The books that come out of nowhere and surprise everyone with their popularity are books that don't follow a trend (because once a trend is identified, it's essentially over). I'd never advocate writing to follow a trend unless you do indeed want to write in a very specific genre.
But - there's always a but, isn't there? It is going to be harder to find a publisher for non-genre/'literary' fiction simply because most book buyers like to buy something safe. Doesn't mean it can't be done - just means you need to be patient and believe in what you're doing - you need to maintain your passion. And, just as I said to someone else below, the best thing you can do to make publishing Australian literary fiction an easier decision for publishers is to buy it - literary fiction always undersells genre fiction, with the odd exception (such as that 21st century masterpiece, Cloud Atlas by David Mitchell).