It seems I'm in the minority, thinking it's harder to quit. Then again, I don't think it's "quitting" to take a break or table a story, even if it's for several years, if the intention is always to go back to it. But....I am an eternal, self-inflicting optimist and it would probably do me good to let go of some of the things I'm holding on to, but I can't. I'm always hopeful I can fix it, or go back to it and finish it, or whatever etc. etc. That's why I think it's hard to quit!
If we're talking about one specific story and not writing as a whole, the same applies to me. If I believe in it, it will take lots of convincing from others to make me change my mind that it's crap and that I should give it up and start over, because *I* can see it so clearly in my own head. That doesn't mean it's coming out well
This was a good question, it really got the ol' wheels turning in the dusty brain! Thanks

kb