The "wildly implausible counterfactual" was a throw away line that had nothing to do with the actual discussion. I was TRYING to start a discussion of the metaphysics of Loki when liar!anon accused me of lying about having a degree in philosophy to try and make myself seem important (?) and then accused me of using my degree in philosophy (that I don't have, apparently??) to justify rape, which had nothing to do with anything I was trying to discuss. Now they have come down here to try it again.

So. In the interest of an actual philosophical discussion, since apparently I'm not allowed to talk about the metaphysics of Loki, counterfactual discussions, regardless of plausibility, have the aforementioned usefulness for mental flexibility training.

It actually IS useful to ask questions in the form of "can you imagine a situation in which immoral act A is justified." I had many an assignment in philosophy class which is basically just that. Most memorably, when we were asked to write essays on when/if murder is ever justifiable. So, yeah, this is a very common training tool in philosophy and has many uses, even when wildly implausible.

It's especially fun in fandom circles because you can use the most wildly implausible circumstances in the arguments and have actual canon backing you up.