Her appearance on the programme has meant that her voice has been heard around the world, but she wasn't a complete unknown when she appeared. She had sung locally, even cut a couple of discs, but her personality wasn't such that she could maximise on that. Even with the support of Simon Cowell's team, it was touch and go if she could go further than the programme.
Talent isn't enough. Talent is required, of course, but you need more. You need to be able to capitalise on your lucky breaks, and you need to be able to create them for yourself. As Jimmy Durante is supposed to have said, the harder I work, the luckier I get. When I was at drama school, the most talented students weren't necessarily the ones who got work on leaving. It was a combination of factors: making contacts, following up opportunities, keeping aware of the industry and where the work was.
Same with writing. If you want to be published you have to develop a range of skills on top of the talent that you have. If life was fair the brilliantly talented would get the rewards they deserved, but life isn't like that. Which, speaking as a non-brilliantly talented person, is a jolly good thing! Make the most of what you have, and don't worry about what anybody else is doing.