From what I can tell, debate.org's system is simply people offering 2 sides, and readers vote. I think a lot of debate can be quantified as two people arguing over what is objectively better for the common good, and such a thing can't really be up for a vote. For instance, it can be objectively shown that we suffer less as a society if we allow gay people to get married, but people might vote as a majority against it due to their own prejudices.
I see nothing wrong with the current points system used by debate.org. However if they work on creating a new and better one it can only stand to benefit the site. There is not a drastic need to change right now but a better system is always appreciated by the users.