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!
Point number one is: I don't understand how you can say, when I am making an argument explicitly restricted to instrumental decision theory, how day to day life is irrelevant. Instrumentalism should ONLY care about day to day life.
With respect to forced sacrifice, my intuitions say I should just do the math, and that the reason volition is so important is that the reasonable expectation that one won't be forced to make sacrifices is a big-ticket public good, meaning the math almost always comes out on its side. I think that you're saying these choices ha...
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!