When someone says “the end justifies means” they are admitting that the means are not justified and they know it. That is an admission of committing an immoral act from the start. But the perpetrator alleges that the moral goodness of the purpose somehow outweighs the moral harm of the process, but they espouse a vague moral superiority to evade judgement and consequences for their admittedly immoral misdeeds. Why should we believe them? If they admit they they will compromise their morals for this, what is to stop them from compromising their morals for something else? Like lying to us about the moral justification for the current misdeeds?
The entire argument is built on moral foundations, but the moral foundations were abandoned in the first step. As soon as deeply reasoned morality is abandoned for temporary exigencies, evil deeds will follow.
We must not put these people into positions of trust and power.