I think Rin got it the most correct though they are heavily based on science, and there main motive is what they believe is the most profitable for the common good. '

They are viewed as evil in her world, because her world is fucked up, lawful evil is the way of the superior races in the world so shes like the polar opposite. 

Lastly she seems evil, because well she kills without hesitation, will fill a room with instant people with poison in a innocent if it will save more.

EDIT
not instant stupid auto correct.