While it's not the worst concept, the drawback would be obtaining the "points". If it's anything similar to the site I'm sure you're referencing, I'm not inclined to believe allowing users to earn points by way of posts would be a good idea. If we were to put a heftier posting restriction on downloads, that's a one-off issue with spam per user. Whereas a points system would encourage rapid and persistent spam to accumulate points. There are always other alternatives of course, such as reputation, downloads per submitted file, etc.. but I just don't see it adding any value to the community.
Besides, as much as we try to shun WebFlake clones, it'd be a little silly if we were to clone our competition. Sure, we could do it and likely do it better, but WebFlake is the original.