In conjunction with yesterday's blog about writing myths, I've been reading on the Novelist Inc loop (Novelist Inc is a group for writers of all genre's who have more than two books on shelves) so many stories from wonderful, mid-list authors about books that editors loved but marketing didn't buy. I'm reading the same stories over and over by multiple authors of series that were dropped and books that never panned out. So it is hugely naive to think that the reason a writer gets rejected is because they are not good enough at the craft- or the book wasn't well written. I learned long ago it was wrong thinking to believe that this kind of constant auditioning wasn't part of the life once you got published.
The good news about this for unpubs is that you are indeed living the author life by writing books on spec and "auditioning" them to agents and editors. Welcome to the writer's life.
(Now I know that some people never have to write on spec- but for most genre fiction in today's market, auditioning is typical. So do not despair! And most importantly do not disparage yourself or your talent. Remember it's the journey not the destination.) Cheers!