For those who reject shouldism what if you live in a society (because we do live in a society) where you or someone you cares about suffer? Heck, imagine one of the countries in the world where you'd never want to live. What if you had to live there, do you still think neither you nor anybody else should strive to change other peoples ideas, values as to effect how the society function? Why are he values of rejecting shouldism superior to your own or others suffering?
If I believed rejecting shouldism to be superior to shouldism, I could on no account be said to have rejected shouldism, since shouldism is the belief in the superiority of one action/value (effect/cause) to another. A shouldist may believe his values to be superior to those of a non-shouldist, but the reverse cannot be.
If I had to live in one of those countries, I might strive to change other people's ideas due to my values. You may say that I "should", though this is a fiction. The preceding sentence captures the essence of non-shouldism.
I don't think there are any "true morals" (outside human values), but I do think we can choose what morals we want and which we think makes sense, and enforce them in a society and live by that.
Schopenhauer said:
Man can do what he wants, but he cannot will what he wills.
To adapt this to your terminology, we might say that Man can choose what morals he wants, but he cannot choose how he chooses. Free will, like the should, is a fiction. Final causes are a fiction. Human morals,
real morals, aren't right or wrong, good or bad. They simply
are, and one either has them or they don't. They may be expedients to humanity's survival or its doom, make us more or less miserable, but they
are. We act because we have values and we have values because we act. Unless I've wildly miscalculated.
Obviously we all have some wishes, preferances, even feelings (!), I don't see why we can't live according to how we function in that regard. Even if using "feelings" sounds so dirty, is there really any good reason why empathy/ feelings can't be part of forming our values? Not to a extreme degree, obviously, but nevertheless empathy tends to be part of why we think and behave the way we do.
I don't see how the part that feelings plays in forming our values good be any
more extreme. As far as I can tell, there's no difference between feelings and values whatever. The latter are just the former considered insofar as they cause actions. The only people who think that feelings need not play a role in forming values, or need only play a supportive or ancillary role, are those who, like that bungler Sam Harris, think that values can be demonstrated, written down, and assimilated by reading books like mathematical theorems, which is about as likely as squeezing blood from a stone.