I think it is too much a reductionist thinking to think it’s the users, not the tools. Math and programming languages (and media like tv or videogames) can easily stand on the sidelines, outside of the range of criticism, by making the claim that it is not the medium, but the users.
But I would argue that knowledge about something is not necessarily within that thing, but around that thing as well. A handle is a handle because we have hands that can grasp the handle. No system in this world is closed (perhaps the universe itself but still doubtful), so any knowledge pertaining to a system (or a tool) must be dependent on its context. A handle acquires meaning because of humans. Same with mathematics, programming, or otherwise.
So I would argue that yes, mathematics can be developed for nefarious purposes. Anything can be. Just because something is more pure and seemingly neutral than others does not mean that thing will stay independent of its context. The outlier example is the statistical farcity and bias in scientific experiments. Take it a step further in the direction of objectivity, and you could also notice that bias plays a role in mathematical experiments.
Another interesting question might be: is uranium evil? Or are videogames evil? Are these seemingly neutral things, containers of things, evil? Or are common manifestations of them, or the way that the medium encourages its content (and the way that Haskell and its ecosystem encourage their application) relevant to the judgment of that particular “container”?
I believe a lot of this has to do with seemingly emotion-less quality of abstractions (i.e. containers). In the abstractions-land, the mathematics land, the “pure” land, only the relevant essence of the thing at hand is extracted, thus the compression seemingly occurs losslessly. However, in the compression from the real to the abstract, we have also lost the sensual, the tactile, the emotional. We go from a soul to a 4.5 million deaths. We go from the wet texture of water to H2O. By compressing, we gain, but also we lose.
A bit sidetracked, but I think any medium can appreciate being examined in such a way.