@MarkusTheGreat, if something has the opportunity to be voted on longer than something else, it inherently has a greater opportunity to collect more votes. Yes, variables such as voter preference could result in the one that was posted later getting more votes, but if variables are equal, the older post receives more votes. That's unacceptable in any contest.
Here's an easy analogy: Imagine that a country is planning an election day. People are allowed to vote for Candidate A for the full 24 hours of the day, while people are allowed to vote for Candidate B only from 1:00pm-11:59pm. Candidate B would be furious (and rightly so); Candidate A is clearly getting an unfair advantage, since they're getting more time for potential voters to place a ballot for them. Yes, come election day, Candidate B might end up winning because they're just so much better than the other candidate that the advantage is rendered moot. But that doesn't change the fact that the election process was clearly unfair.