Hmm I can understand why an uncompleted fic can be a real pain to the readers but I also understand that sometimes you get to a point in writing a fic where for whatever reason you seem to be incapable of writing any more.
I think sometimes readers forget that it can be annoying to the author as well cause I doubt anyone likes running out of inspiration/ motivation for their fic.

Personally I like the idea the kink meme (I believe it was them anyway) had where you can put your incomplete fic 'up for adoption' as it were.

That way there's still a chance of it being completed by someone with the motivation to do so.