Rejectomancy is the art of reject divination, or trying to figure out what the editor or agent really meant from the few short sentences of the rejection letter. By and large it is a fruitless and frustrating pursuit, especially with form letters. Even with personal rejections it's not a great idea, though some of those can be quite clear. That's because what a reject means is very simple:
This story did not work for this editor on this day. That's it.
The best illustration I've ever had of this principle comes from a mistake I made, emphasis on the word "mistake," as in do not do this.
I have something like 400 rejections to date. One of them is for a story later sold to that same editor at that same magazine with no rewrite. At the time I had something like 25 stories out making the rounds. When you have dozens of stories going to dozens of magazines and anthologies with wildly different response times, careful bookkeeping becomes very important. I'm pretty good at these things and keep a spreadsheet with pages arranged by story, by market, and by editor. Unfortunately, I somehow failed to log the particular rejection in question (a personal). It was from an editor who had bought other stories of mine and who was actively looking for me to submit more as he told me at World Fantasy a few weeks later.
At that time he asked me what I was sending him next. Having failed to log this particular story, and having forgotten he'd rejected it, I mentioned the title, gave him a two sentence pitch and promised to drop it in the mail ASAP. So, I did that. Then about two weeks later, I stumbled on the rejection in my to-file stack and realized what had happened. Aiee! I thought. This was and is a significant faux pas. So, I quickly banged up a note admitting to and apologizing for my mistake and offering to pull the story. It crossed with the acceptance and contract in the mail.
Same story, same editor, different day, different result.
I am not suggesting that anyone should resubmit a story to an editor who has already seen and rejected it, far from it. I screwed up. I also got lucky.
So, the moral of the story is: reject = not for this editor on this day, send it on to the next one. Nothing more. Nothing less.