I'm just middle aged and lost all energy for unproductive discussions. The second another poster posts something genuinely hostile, like "touch grass" kinda shit, I'm just done talking. Also if we're six comments in and the other guy won't even admit to being wrong to the thing he said on comment one, despite me doing twenty minutes of research to prove conclusively that he's wrong, I don't want to waste another second of my life on him.
I gotta have 10% of the "disengage" comments on this site.
I'm just another Internet random but, FWIW, I don't think it's improper.
I read something recently that I think is relevant. It was just someone else's hearsay, not a quote from a philosopher or someone famous or something, but worth paraphrasing here.
It went something like, "nice people are nice because they don't have patience for bullshit."
The context was an explanation that having boundless patience for, e.g., unproductive arguments, isn't being nice—that's just letting people walk all over you.
Being nice comes from the mental tranquility of knowing that you will not hesitate to walk away from unproductive pursuits.