Parsers

[rhemi1]

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You can tell the boss is dying slowly, or mechanics aren't meeting their required checks, but you can't tell who or why. Sure, I could keep my eyes glued on the Dragoon the whole fight to ensure he always have Heavy Thrust up, and watch the Black Mage to ensure they're always doing their correct, optimal rotation, but there are other things to worry about. Especially in Twintania...that is not all 'boss rotations'. If your dps is lacking, you WILL wipe at one of the many dps checks in that fight, be it conflags, snakes, dreadknights or just the plain old enrage. Titan? You won't get heart down, and even if you do, you'll lose to attrition in the end if your dps is too slow. Even something like Turn 4, if your dps is too slow, you'll end up with unrecoverable situations such as the Dreadnoughts eating spiders because they didn't die fast enough.
Parsers are tools, and how they're used depends entirely on the person. They help a lot when trying to determine who needs help and how, but no decent raid leader RELIES on them.

I don't know why people get so hung up on helpful tools, there to aid them. Sure, a jerk can use them to harass, but guess what? Jerks are jerks. Remove the parser, that jerk is still, well, a jerk. He's not going to become a nice person, suddenly.