It's not about your employer being your identity; It's about empathy and whether your choices improve or worsen others' lives.
> Don't blame the soldiers for the fault of the generals.
Since you apparently like military analogies, I'll quote one of the Nuremberg Principles, which---as far as I am aware---are not an American invention:
"The fact that a person acted pursuant to order of his Government or of a superior does not relieve him from responsibility under international law, provided a moral choice was in fact possible to him."
This is a pretty sensible principle, because it's the soldiers who enable the generals. Similarly, if you're a developer (unless you're really terrible) and you work at Zynga or any other company, you're enabling your employer.