You can't just say 'Oh scale the ability down'. A lot of the lower level dungeons were designed around very minimal aoes and not a BLM triple flare, thus you could reduce an entire pull up to a boss with one character even /if/ the ability is properly scaled down because they are designed to be worked on one at a time and so have lower health pools to make sure you can do so in a reasonable time. Hell could you imagine a PLD before shield oath trying to hold threat on a BLM or a SMN with their full level 60 aoe rotation? I don't think you can spam flash enough times to overcome the sheer amount of burst a BLM with a full aoe rotation can pump out. As Fluffernuff said... its a disadvantage to new players who are learning and very much a toxic environment starter.