I realize this issue has been declared "closed," but there seems to be immense support for reconsideration. Maybe all pleas will fall on deaf ears. But I wanted to add a second answer to this question to point out a marvelous example of why this would be a good feature to have.
On the ides of June, somebody asked a question on the English Stack Exchange:
Why do we have different starting pronunciations of station and sun? Station is pronounced as e-station while sun simply as sun. Is the difference due to the fact that the second letter is a vowel in sun but not in station?
A dialogue ensued in the comments, with several users asking for more clarification. "That's not how to pronounce station!" said the users. "But it is!" insisted the O.P. All the while, the question accumulated downvotes and close votes from puzzled members.
Five hours later, two users – apparently typing at the same time – wrote very helpful, knowledgable answers that unlocked the mystery, by informing the rest of the community that the O.P. was refering to anaptyxis. Suddenly, what had initially seemed like a very silly question had become a very enlightening one; the stone that the builders rejected had become a cornerstone.
As of this writing, the question – now half a day old – teeters on the brink of closure, with 4 close votes cast. One more vote, and the question will be relegated to the boneyard of closed questions.
Yes, I realize there's a mechanism for reopening the question, but why wait for a decisive vote to be cast, before pursuing that? Why not allow users to rescind their close votes on what turned out to be one of the most interesting and informative questions ever asked in the forum?
As I said, I may be pounding my head against a brick wall with this anecdote. But one never knows. After all, the U.S. Supreme Court once ruled in favor of slavery. Institutions can change.
:P)