Today's defence is mounted by Peter Salisbury, a science fiction writer from the UK. He writes both serious, intelligent sci-fi, such as Passengers to Sentience, and has also published a book of robot limericks. He's the only person I've come across to say the original version of Bladerunner is the best version of the film, but he defends this viewpoint strongly on his blog...
In my teens, twenties and thirties I tended to avoid short stories. However when I was around twelve, I recall having a short story anthology which made a particularly strong impression. Those were also the days I read Marvel comics and Dan Dare, all of which effectively were short stories and cracking good adventures they were too. I think many of us enjoy short stories without realising it. Tin Tin, Captain Pugwash - all short story favourites. How many popular magazines today don't have at least one short story per issue? Very few, I would guess.
We are all surrounded by short stories. When we meet a friend and ask how they're doing, we don't expect a detailed report of the last six months, we expect, effectively, a short story. Here's another: the TV news anchor person Ms Reids-Knightly speaks in a series of headlines before announcing, 'And here's Brian with the story.' Again, it's a short story. Then we have podcasts, newsfeeds and newspapers themselves. Does a newspaper consist of a stack of book-length treatises on a range of subjects? No, it's full of short stories!
'Ah,' you say, 'but these are not fiction.' Oh, really? Change channel, chose a different newspaper and you'll get a different version of the same thing: 'The country is going down the tubes.' or 'The country is on the up.'. Who was it said 'Never let the truth get in the way of a good story.'? There's that word again.
In the past, many Science Fiction writers began with short stories which were published in magazines or collections. Later they developed the ideas further and from them grew full-length novels. In that sense the short story had a purpose as a developmental tool. Another way in which short stories can be very effective, is to set a scene involving a set of conflicting personalities and/or events, then leave the characters hanging, with a problem to solve. I like those sort of short stories as much as the ones that come to a neat or unexpected conclusion. With the short story which has ended with everything still up in the air, the ideas linger and go around in your head. Then you have the additional pleasure of examining the different possibilities of how things finally played out.
Check out Peter's stories via his Amazon author page, or his blog.