When does an indie writer ignore people who are telling her what to write?
Short answer:
When she's making money anyway.
Long Answer:
What I'm talking about here is subject matter, not grammar and spelling.
(Seriously, you should always fix grammar and spelling, assuming the critic is correct that something is wrong. Guess what? Sometimes, the critics don't know as much grammar, spelling or factual research as they think they do either.)
Many of the so-called experts, and that includes folks from both the trad and indie published spheres, have no freaking clue of what they're talking about. So how do you know when they're right and when they are wrong?
You don't. Sometimes their criticism has nothing to do with you or your story, and everything to do with the critics own hang-ups. So, here's some things to think about to keep you on your path, not someone else's:
1) Write what you like to read
This is not the same thing as writing what you know. A lot of people write to market, i.e. if sparkly vampires or stalkers are hot, that's what they write. These are the same people who deride you for not following that trend. But once the market's saturated with crappy knock-offs, the readers stop buying those books, and everyone loses.
If there's a genre you love, and you can't find enough material that can keep you satisfied, then write a story in that genre. Just because it's not the hot thing at the moment doesn't mean it won't sell. There's lots of readers bemoaning the loss of sweet romances, westerns, and gothics right now. If you're one of them, why aren't you writing one?
For example, I like BDSM stories with romance, which is a subgenre of erotic romance. There wasn't a whole lot when the big publishers tried to ride the erotica wave launched by Ellora's Cave in 2000. So I wrote a couple and published them under a pseudonym. They sold, and they continue to sell steadily.
2) Study the market
Sounds contradictory to No. 1, doesn't it? But I'm not saying write to the market. What I mean is there are times when you can anticipate trends in the genres you love.
I adore fantasy and paranormal. In 2004 when I got serious about having a writing career, vampire romances were peaking and werewolf romances were on the rise. So I considered what would be the next big thing, i.e. which monster would take center stage.
The year before, an odd little duck of a comic book called
The Walking Dead had been released. George Romero was still writing his zombie movies, and they were as popular as ever. However,
Zombie Love was too off-the-wall for trad publishing by the time it was finished in 2005. In some ways, it still is. But I indie published it anyway, and it sold.
Does anticipation of a market trend always work? No. I couldn't have predicted BDSM romance taking off like it did. Which leads to...
3) Accept that you may love and write in a niche, and it's not a bad thing
Contemporary romance may be the most popular and best-selling genre on the face of the planet right now, but if you absolutely despise it, don't write it. Seriously. It's a good way to burn out your brain. And if you did a half-assed job because you hate the genre, your book won't be differentiated from the thousands that are out there. Furthermore, just because romance readers are voracious doesn't mean they are idiots. They'll one-star your book in a heartbeat if they think you don't respect them or their favorite genre.
The great thing about indie publishing today is that freaky subgenres that can't sell enough to sustain a multi-national publishing conglomerate CAN sell well enough to support the dozen or so writers that adore that particular freaky subgenre.
For example, M/M romance, lactation erotica, and serial killers as heroes are niche markets. Indie writers in these markets are doing very well because they enjoy the subject matter and they respect the readers of that subject matter. Very rarely would a trad publisher touch these topics, if it all, whether because of their own squick factor or the relatively tiny sales. However, those relatively tiny sales can still pay your mortgage if you write about it.
Finally, to paraphrase Internet Rule 35--if no book on a new subgenre is found at the moment, one will be written. Be the one to write that book!