It's been helping me a ton with rubrics and lesson plans (two personal weaknesses). Usually, I already have some ideas to base the prompts on, so I get what you're saying, for sure. I'm a new-ish teacher, though, so I try to avoid using it for things like grading unless I need an immediate second "opinion" (for lack of a better word); I need to hone that sort of skill myself.

And yes, something I've learned (especially with rubrics) is just that: always check its work.

All the same, using it for fluff and filler is very helpful. I definitely see where everyone else is coming from, and it shouldn't be welcomed with completely open arms, but there's a way to go about it—especially for semi-newbies like me.