It sounds harsh, but the reality is that not every project succeeds. In a sense, writers learn this early — with rejected queries, rejections from magazines, criticism from honest writing groups, and more. However, there also seems to be a pervasive mantra throughout the writing community that if we just don't give up on a project, it will succeed. Not only is that untrue, but believing that could also be harmful.
For one thing, sometimes a project needs to be shelved. Sometimes, no matter how much you work at it, a story just won't come together. (Occasionally, it won't work for now, but could be reworked many years later, though you still first have to set it aside.) That's a part of reality more experienced writers understand and accept, though somehow it's still almost never discussed. We're so busy being encouraging, we ignore the fact that sometimes the best thing you can do for a project is realize your current one isn't right, so you can start the next one.
The scarier part of failure, however, is after your project has already made it out into the world. We as a community constantly discuss success — the writer who just signed with an agent, or received a multi-book deal, or debuted with a bestseller — but ignore the part where many books, indie or traditionally published, never recoup their expenses.
I think part of the reason we're so afraid to acknowledge this reality is that we somehow equate a project failing with the person being a failure. And there is a monumental difference. While it's important to have benchmarks for success for both our projects and ourselves as individuals, those benchmarks should be distinct.
There are thousands of reasons a project could fail, even if the person behind the project does everything "correctly." Some amazing books never make it, while some books of questionable quality skyrocket. Something like 90% of start-up companies close within their first year. Acknowledging that a project is failing, or has failed, allows us to move forward, hopefully learn from the experience, and have a better chance of our next project succeeding. Pretending that if you just try hard enough any project can be salvaged, however, can mean wasting time, effort, and even money. Walking away from a project that is failing doesn't make you a failure, whether that project is a book, a job you hate, or even a career trajectory. And there is a difference between doing that and giving up on yourself.
So let's stop defining our self-worth by whether our current project succeeds, so that we can in turn stop pretending every project, with enough work, could succeed — so that we can ultimately stop making people whose projects fail feel like they are failures. (Nice circle, right?) Infinite supportive platitudes don't guarantee success. Acknowledging failures, discussing failures, and helping ourselves and others learn from our failures, however, will offer us all a healthier environment as we work toward our goals.