There are a number of reasons why we are doing this, and I’d be happy to discuss them below. However, the primary reason is this: The aggregate sharing of the community is not what we want Hubski to be guided by.
As always, feedback is appreciated!
It means that Hubski will act more like a traditional forum in which every post is equally regarded in terms of visibility. It prevents homogeneity to some degree, but it does so at the cost of collective quality control. This becomes more important as the community grows larger and as posts become more frequent. The front page may become simply a long and disorderly queue of whatever was last submitted without any regard to what the community decides is particularly interesting.
Of course, Digg and Reddit are examples of what happens when collective quality control fails miserably, so I can't exactly advocate their voting systems with any real confidence. There must exist a middle ground, somewhere, by some means, which allows for quality content to become easily visible without also stifling intelligent yet unpopular dissent. I hope that, with Hubski, we can reach this middle ground, or come as close as possible. Here's to a bright and positive future for everyone involved with this growing community. :)