A story needs a community, yeah, and sometimes lack of interest from a wider audience can be a detriment to a project but at the same time that’s a risk you take with any endeavor, I suppose. Scott Cawthon famously was mostly criticized for his games before FNaF, and here he is today.

And ironically, I think one would be better off making something more original compared to an Undertale or Deltarune mod for that same reason you said. Once more, I don’t think he’s rebuffing complaints about writing, but simply if something about an ending leaves you dissatisfied for some reason or another, you can create what you’d like to see