Is the argument here something along the lines of; I find that I don't want to struggle to do what these values would demand, so they must not be my values?
I hope I'm not seeing an aversion to surprising conclusions in moral reasoning. Science surprises us often, but it keeps getting closer to the truth. Technology surprises us all of the time, but it keeps getting more effective. If you wont accept any sort of surprise in the domain of applied morality, your praxis is not going to end up being very good.