We say the ends justify the means... but if we poison the means, do we not also poison the ends?
The word "justify" is the tell here. One needn't justify something that is incontestable. To justify something implies a post hoc rationalization, as opposed to a logical and well-considered decision and/or course of action. Isn't this fairly obvious and a relatively easy argument--the case here should be closed, should it not?
I have always disagreed with "the ends justify the means" - doing shitty things is still shitty even if the end result is seen as a gain.