Feedback is essential to any creative process. Over the course of the last two or three years, I have made about 670 short story submissions. Less than three percent have been placed, and probably less than one percent paid any money. That is a kind of feedback.
On Blogger, there are stats. You can see how many page hits a given story might receive. If one story gets a lot of page hits, and another story, of different subject matter, gets a few, then obviously the savvy writer will write more stories on the more popular subject matter.
On my Smashwords dashboard, there is a 'stats' button. It takes me to a separate page. If I put out a link on Twitter, and an hour later see that I have received 'x' page-hits, then all I have to do is put out ten links to achieve ten times 'x' page hits, and after a while, I can figure out exactly how many page-hits it takes to sell a book. This can be compared to how many page hits I get without any promotion at all.
The difference is pretty obvious.
Now, if I put out a link for Smashwords and get fifty page hits, then it's a pretty good bet that if I put out a link leading to a product on Amazon, or Barnes & Noble, or Kobo, or Sony, then I will get the same number of pages hits, approximately. At this point the relative market share of the retailer comes into play, and this skews the numers, but feedback is still essential. In purely physical terms, try doing anything without feedback. Try walking without eyes and a sense of balance, and no feeling in your feet.
For many short story rejections, all the editor says is, "Not quite what we are looking for."
That's too bad, as I had this one story with a real bad error of fact in it. No one told me! And of course I kept on submitting it around. It was only later that I discovered the error. Mentally reviewing just how many places I submitted the story, I sure wish someone had told me about that.
A little bit of feedback would save everyone a bit of time in the long run, put it down to 'species altruism' or whatever. That's because one editor's effort might benefit another editor's publication in the short term. However, in the long term, it would come back to the editor's benefit, as I would be less likely to submit a bad story, over and over again.
I'm always glad to receive feedback or criticism, as in the long run I am better off! That's called, 'enlightened self-interest,' and I never take it too personal.
I just figure the editor was having a bad day, and my story wasn't helping any.