Although the name "boost" is a little odd. kbin is more than than just a link aggregator. kbin is also a semi-blogging platform (View the microblog feed rather than threads) that interacts with Mastodon. If you boost something, it is the same as reblogging (re-tweeting) a post and generates a reblog post on Mastodon. The developer is going to change it to where the up and downvote impacts reputation rather than the current boost and downvote button. A technical oversight but they acknowledge this and plan on changing it in the future however internet points is not really a priority so no one knows when the change will roll out.