I've found many questions here regarding this 'feature' and many answers explaining how it works, but none showing any 'philosophical' concept behind it. i.e., why is it here? Is it helping to make site better?
For example, just now I made a downvote, retracted it to think a bit more, left a comment with explanation and tried to downvote again. No game.
And this is not the only real-life situation when value of this 'feature' is doubtful. There're plenty on this meta.
So, what was the primary reason to introduce it? A flow of people who change all their votes on daily basis?