There's a journal I read a paper in I wanted to respond to. The journal is open access, has no fee, and I have enough for a short paper (less than like 5 pages, there are no size limits). Writing this would take minimal time away from more important work. The journal is...not great. I don't think it's predatory (it's free to publish and is peer reviewed), though it might be.
I am a grad student. This response has nothing to do with my main research.
Would this come to hurt me later? Would people look down on me for having a short, goofy paper in a poor journal? What could they do that's dishonest? Even if they straight up steal what I write, I don't really care that much (though I would obviously not work with the journal again).