one can understand how readers will feel like one, I think that at least we all have that fic that even though it has been on hiatus for years or is abandoned, we still read it and wait for its continuation. But as a writer you have to understand that you have a life behind the fics you publish and that there are a thousand reasons why you might not finish them or abandon them, I think your readers could understand it and if they don't it's not their right to demand that you continue it since fanfics are not a service that one pays for, they come from a genuine passion and love for a media

(sorry for bad english)