The mechanism of “evil” here is vulnerability to capture. If there’s a gun on the ground and a stronger and weaker guy fight to claim it, the stronger guy will likely end up with it, making him even stronger. Eventually all the guns are in the hands of the already powerful, with the most powerful having the biggest guns, and no opposed forces restraining them. That’s the sort of “evil” that “can’t be evil” tries to restrain. The kind pointed to by the proverb, power corrupts, absolute power corrupts absolutely.
Most technologies are like guns. They tend to get aggregated and captured by those who already have a lot. Technology, in other words, generally exhibits preferential attachment to power.