How Short is Too Short?

I write long short stories. Probably a holdover from my days of writing literary fiction. Four to five thousand words often feels right to me.

But as an zine editor pointed out to me Monday, that's long for online reading. So I cut a 45oo word story to 3000 words in 30 minutes. Not hard at all.

Why didn't I see all those unnecessary words before I sent it out? Does this happen to you? Or, alternately, do you read stories that feel longer than they need to be?

Or are we all getting to be too impatient in wanting such bite-sized stories. Are those extra words the ones that give it depth, grit or meaning? Have we sacrificed something else in the name of brevity? If you can read a novel on a Kindle, why is a 5000 word story long for online?