But the times they get it hugely wrong—as with Rowling—are hugely publicized, while the public hears nothing about the tens of thousands of manuscripts that are turned down for good reason. (And a good reason may have nothing to do with the quality of a manuscript and everything to do with whether it fits well with the rest of a publisher's line or whether an agent has contacts with editors who might be looking for such a manuscript. Most of what they turn down, though, is truly awful.)
However, sending a book or series out to agents and/or publishers need not be the end of the line these days. I do think for most writers it's a good place to start, because how do we know whether someone will snap it up with a big advance until we've tried? But if that doesn't work out, other options remain. So:
The downside is that could mean some half a million edited words written and going nowhere
may not actually be the case even if it hasn't found a home with an agent or a publisher. Once the writer has given the book a decent chance at selling through those channels, they can always self-publish—there are plenty of good ways to do that inexpensively—and see if the books do well that way. When you don't have all the overhead of a publishing company, success in terms of sales can be measured rather differently, and if all the work of writing and editing is already done, why not see what happens? It could establish a career, or it could sink like a rock, but it's a
chance, which wasn't available to writers twenty or thirty years ago, and better than leaving the books languishing on a hard drive forever.
Besides, at the very least the books were a learning experience, teaching lessons that can be applied later. And if it was something you enjoyed writing, then you at least have that on the plus side of the how-you-spent-your-life balance sheet. It's a consideration not to be scoffed at either, because from what I have seen, those who write
purely from mercenary motives, and write things they despise and don't enjoy writing but which they think will make them rich, whether they be successful or abject failures they frequently display a degree of bitterness about the process that people who write what they love and truly believe in rarely seem to develop.