Why are skill speed & spell speed separate stats?

[Giantbane]

Perhaps to keep in mind for future content (perhaps NIN even, depending if Ninjutsu has a cast time) for melee/caster hybrids.
PLD is another example - since PLD doesn't have any spell speed gear (minus materia melds), it means that casting spells like Stoneskin will be at the default 2.5secs recast.

That doesn't make any sense. Skill speed is already a weak stat, but it would be particularly weak for any class if it didn't apply to all their abilities.

How is a PLD casting stoneskin a few tenths of a second faster imbalanced? PLD already has to full stop DPS & threat entirely to stoneskin, whereas the relative warrior equivalent (self heals) is performed while they do damage.

[Shurrikhan]

Perhaps to keep in mind for future content (perhaps NIN even, depending if Ninjutsu has a cast time) for melee/caster hybrids.
PLD is another example - since PLD doesn't have any spell speed gear (minus materia melds), it means that casting spells like Stoneskin will be at the default 2.5secs recast.

To be honest I feel like those two examples are good reasons to make Speed affect both types. As it stands it's a near worthless stat except in reaching certain plateaus (and still slightly inferior even then). It affects only GCD direct damage - no auto, no oGCD, and no DoT - while Crit and Det both affect all four damage types. If it won't be balanced in a more standard way, it might at least quicken song and Stoneskin casts...