Fortran has been extensively used for nuclear weapons development. Let's stay away from Fortran!
C was and is widely used in weapons control systems. Let's stop using C!
Computers themselves were initially designed for artillery fire control, with an explicit intention of killing people. Let's not touch the technology with such a foul pedigree.
This can be continued ad nauseam, until the whole of the civilization is marked as indecent. Nearly every scientific discovery and techology achievement has been used, or attempted to be used, for some purpose one might find objectionable.
Instead we could realize that tools are outside morals. A knife could be used to cut bread or to cut throats, and it's not the knife's decision, but that of its user. The very same thing applies to everything, from nuclear fission to functional programming.
If you know what's the right, virtuous thing to do in the world, do not hesitate, go and do it. Use the most fitting tool for that job. Do not mind if that tool is used for whatever other, less noble purpose, it's not the tool's fault.