When I commit to a proposal on Area51 it's done after careful thinking, not something that is done lightly.
(source)
When I uncommit, I expect family and friends to ask me to reconsider:
Please, at least a small confirmation box? Or friendly robot explaining the consequences?
Being serious for a moment, people sometimes put long comment when committing and might click Uncommit by sheer mistake, although it's easily "undoable" by committing again, it's irritating.
You used to be so committed. Remember when you told [Proposal Name] "[Your commitment comment]"? Do you no longer feel that way? What changed? How did that make you feel?