Note when you convert from Honor - Justice, or Justice-Honor you do it at a loss, it takes 325 points in one to get 250 in another. I think it's mostly for players that prefer one type of play over another to give them something for the points that would otherwise go to waste. It is a handy way to pick up points in your least favorite way of playing. I myself love PvP, and a BG weekend is faster to get honor points than chain heroics are (not to mention some pugs just are fail)