The reason I thought you didn't understand what I was talking about was that I was calling on examples from day to day life, this is what I took "instrumentalist" to mean, and you starting talking about killing people, which is not an event from day to day life.
If you are interested in continuing this discussion (which if not I won't object) let's take this one step at a time; does that difference seem reasonable to you?
The day to day life bit is irrelevant. The volitional aspect is not at all. Take the exact sacrifice you described but make it non-volitional. "torturing yourself working at a startup" becomes slavery when non-volitional. Presumably you find that trade-off less acceptable.
The volitional aspect is the key difference. The fact that your life is rich with examples of volitional sacrifice and poor in examples of forced sacrifice of this type is not some magic result that has something to do with how we treat "real" examples in day to day life. It is entirely because "we" (humans) have tried to minimize the non-volitional sacrifices because they are what we find immoral!
Admitting to being wrong isn't easy, but it's something we want to encourage.
So ... were you convinced by someone's arguments lately? Did you realize a heated disagreement was actually a misunderstanding? Here's the place to talk about it!