I believe this is the biggest beef I have with the publishing business. Being an engineer, subjectivity doesn't always figure into things (though you'd be surprised how heated it gets when it does...engineers can be a brutal bunch).
In publishing, everything is subjective. Certainly, there are some guidelines (appropriate usage of the English language, submittal of the appropriate genre to the correct outlet, etc.), but all in all, everything comes down to whether a specific person likes your material at a particular point in time.
Take for example, a recent short story of mine. I worked it up, polished it, polished it some more, revised it and polished it even more. Then, I sent it to some readers for their feedback.
90% of the readers loved it...and not just friends of mine. There were only a few that didn't, and I even worked a few of their issues into the final product.
So, I've submitted it to a pro outlet (just mailed it out this morning). I have no delusions of grandeur, it's likely going to get rejected. And (if so) it will be because one person didn't care for the story at the very moment they received and read it.
Publishing is weird.