This one particularly resonated with me:
4. Solipsism. One miserable person being miserable. This was the most common and depressing failing. Unrelenting monotony of one single, invariably miserable and oppressive viewpoint. No sign of concern or even mention of any other character, nothing other than one person’s dreary moaning. If you are not interested in other characters, at least make it funny.
I can remember one point when I started writing when I had a phase of writing this sort of story. I think I thought it was 'being literary'. Luckily, I bored myself so the phase passed quite quickly.
It's easy to forget that stories are essentially about entertainment. In short stories you can get away with miserable, unlikeable or irritating main characters in a way you couldn't in a novel, but they've still got to be entertaining. Stuff needs to happen. Change has to happen (and not of the sort, things were bad and then they got worse). We don't want to spend time with miserable people moaning in real life, so why do it in a story?