I try to use down-votes judiciously, and only do so when I truly feel that the -1 is deserved.
Still, at least a couple of times I have revisited the question/answer the following day, and found replies that made me regret my down-vote. For instance, I may read a response that points out subtleties of the original post that I hadn’t considered.
In cases like this, where I no longer feel that the down-vote is warranted, I’d like to be able to uncast the vote. But, of course, since up/down votes are locked-in after an hour or so, I’m prevented from doing so unless the original post is edited.
I can see the logic in locking up-votes, which might prevent retaliations from disgruntled users, but I fail to see how disallowing down-vote retractions is beneficial.
Is there a valid rationale for locking down-votes?