Originally Posted by
TouchandFeel
If you give PLD an offensive ability that uses gauge, then any usage of a gauge-based defensive ability will be seen as a dps loss and avoided as much as possible which will screw up the balance of PLD's defensive capabilities.
There is a reason that resources such as job gauges are isolated to only defensive or offensive abilities on jobs, or reimburse a free offensive for a defensive usage in the case of TBN on DRK. The value of defense and the value of offense do not correlate and translate directly between each other because they are inherently different and when you force them to be payed for in the same resource, you force their value to have to be weighed against each other which as already established is problematic. With the "damage is king" meta of this game, value will always be skewed towards offense and therefore undervaluing defense, and so when given the choice on what to spend something on players will always be inclined to go with the offensive option at the exclusion of the defensive option.
The only way I could see making an offensive ability for PLD that costs gauge work would be if it was also gated by a long enough recast timer that it would spread out and restrict the usage of the offensive ability enough that it would not interfere much with the necessary regular usage of defensive abilities and their gauge consumption.