Sharing goals is definitely a tricky decision, as you note. I think it has even more subtly than your proposed dichotomy, though.
Getting positive feedback just for proposing a goal takes away the positive future reward, but you still have reason to avoid the negative future reward of failing your commitments. Getting negative feedback early gives a positive future reward of showing people up, but this is little better than the future reward would have been anyways and comes hand in hand with an increased fear that your detractors will indeed be right.
Your point about avoiding early and undeserved praise is an important part of maintaining motivations, but I think a better solution would be something like a ring of friends that strongly support goal-achievement and stretch goals as virtuous and frequently check in with each other on incremental progress to incentivize goal-maintenance.
Sharing goals is definitely a tricky decision, as you note. I think it has even more subtly than your proposed dichotomy, though.
Getting positive feedback just for proposing a goal takes away the positive future reward, but you still have reason to avoid the negative future reward of failing your commitments. Getting negative feedback early gives a positive future reward of showing people up, but this is little better than the future reward would have been anyways and comes hand in hand with an increased fear that your detractors will indeed be right.
Your point about avoiding early and undeserved praise is an important part of maintaining motivations, but I think a better solution would be something like a ring of friends that strongly support goal-achievement and stretch goals as virtuous and frequently check in with each other on incremental progress to incentivize goal-maintenance.