Never underestimate the power of words, like how some employees go ballistic when they're called resources "like we were cattle". Well tough you're hired to do a job and in that context you're just another input, like the bricks and the blender you need a bricklayer to make the wall. I usually sarcastically agree they're right, the proper term should be prostitute since we're pimping out our brains for cash.
I know that no matter how much they care about my physical and social well-being it's ultimately a means to an end and I'm not the end. The same way that no matter how much I care about my job it's ultimately a means to get compensation, perks, promotions, goodwill, recognition, references and so on, it's their goal not mine. That's the core of an employer-employee relationship, they're not my friend, family or partner and nobody should lose sight of that.
Which is not to say we shouldn't be on good terms, I think there's a lot of win-win in that. But I don't get angry when they refer to me as a tool to get a job done. And if they try any cog in the machinery analogies, I don't mind going to a restaurant analogy to say it's more like what happens when you drop-in replace tenderloin with shank because they're both beef. Hint: It's not going to be very good. Which I suppose is comparing myself to cattle. Moo.