He wasn't saying Manafont was worthless... he was comparing FFXIV Burst as a "two hour" ability being as useful as Familiar from FFXI.
Have you even played BLM?
Burst hardly receives a substantial damage boost from having less HP. Rage of Halone did this once upon a time, it doesn't anymore. Think about why SE removed that. Burst will not save an FFXIV party in the situation you just described. The damage is not high enough currently for Burst to be an "oh shit gotta kill this now" ability. It barely outdamages what THM already brings to the table and those abilities don't have 15 minute timers.
