In this specific case, X is:
"Personally, my take is the opposite: if you are an ethical person find the very worst company that you are still willing to work for and try to change them from the inside"
with the response, Y: "join ISIS' IT department"
What is the refutation of this particular "X implies Y" you would have used instead? Is there one that doesn't require refining X and instead attacks the Y? X is already verbose, and adding additional verbiage does not help the case (IMO)
In this specific case, X is:
"Personally, my take is the opposite: if you are an ethical person find the very worst company that you are still willing to work for and try to change them from the inside"
with the response, Y: "join ISIS' IT department"
What is the refutation of this particular "X implies Y" you would have used instead? Is there one that doesn't require refining X and instead attacks the Y? X is already
Perhaps their derivation of the absurd conclusion from the claim <X> was based on a misunderstanding of the claim <X>, or perhaps their derivation of the absurd conclusion from it was based on some fallacy, or some false assumption.
But reductio is a valid logical step, so long as we have the validity of the argument that the absurd conclusion follows from the premise.