I know. It's not a popular phrase. It invites much critique... words like lazy, apathetic, selfish. But maybe it's worth examining under a different lens.
For instance, I've learned that it's not my job to change the consumerism of our society. If I believe that it is my job, I attempt to carry the weight of the world on my shoulders with every decision I make. I feel shitty about buying much of anything... even more so if it's not something I'll use to it's fullest capacity or if I haven't researched the company's efforts toward corporate responsibility. Given the ridiculous number of decisions I'm faced with each day (thank you, modern living), that quickly becomes paralyzing. My frame crumbles in despair, and I'm unable to offer any actual help.
But, I see that it is my job to live above the bar of blind consumer. I can be intentional in my life and decision-making. I can ask questions like -- what I'm supporting with the purchases I make? -- but, each decision doesn't need to be perfect or induce guilt. For a perfectionist like me, "not my job" is a reminder I need. It's a healthy statement to make and hear. Without it, I operate under a delusion that I need to play the role of God. But he's got that covered without needing any assistance from me.