Oh, trust me, I do it too--someone recently pointed out that I wasted 100 words at the beginning of Castle of Masks, and they were right, so I baleeted it. I hope people continue to tell me when they find flabby prose. Snip snip!
There's a finite amount of space in a short story. Most markets seem to want something like 6,000 for a very fat submission. Some places will stretch it to 8,000 or 10,000, but they're rebels! And yet I keep finding people who are willing to waste several hundred (or even thousands of) words to tell me something as simple as, "This woman is standing on a hill," or "There's a war in this country." If there are other things simultaneously woven into the scene of the woman climbing a hill, that's fine and dandy, but if I read about her walking to the top of the hill and then the story starts, we have issues. Chiefly, the issue of me telling you to knock it off and then hitting the little "X" on the story's tab and moving on to something different. I just read an almost-amazing story (Hi, G!) which made that mistake, and even though I wanted to read more because the writing was so good, I was too grumpy.
This post brought to you by a red pen and too much time spent in the Water Cooler and OWW.