I'm not even going for reductio ad absurdum here, this seems to literally be what you're saying.
I simply said, as did dcposch, that to talk about ethics independent of ability is useless from a functional perspective. And to go farther, that applying anything other than amorality to internet actors is without functional value.
A rebuttal, if you feel otherwise, would take the form of "No, I believe pure ethical evaluation is still useful because..."
The penny you pick up on the street, despite any argument to the contrary, hasn't been put there for safekeeping. It's lost and it's value is so low that it's immaterial if you return it or not. Actually the loss in productivity and the impossibility of the task is such returning it, unless you saw the person who dropped it, is probably a negative thing.
Now if that was $65000 then you might keep it because you can and it benefits you, but the ethical thing to do is to attempt to return it to its owner.
Compare that to a weak password though, as far as you know it isn't even lost. You're just assuming that it will be stolen so it might as well be you. Do you feel the same way about the contents of other peoples houses? Pretty much anyone who wants has the ability to enter your home, we don't do that because of ethics.
Because most people feel even a bad lock changes the ethical calculus. Because ease of transgression has a direct bearing on the actually realised ethical result.
The issue with the original "that's not ethnical" comment was not "Yes it is" but rather "You're right, but how is that relevant to this discussion?"
If I can brute force a password with a TI-83, then that should be a different conversation than if I can do so with a few hundred million dollars, a backbone tap, and a government cluster.
To argue otherwise is navel-gazing about whether the red I see is the same red you see. Maybe? But more importantly, what does it matter?