I'ts all based on stat weights.
Your full thrusts will do more damage if you have the max amount of det and str possible, which might not be the combination you want for the most DPS in an encounter.
For example, having 50 crit over 10 det is definitely a dps increase according to stat weights, but the 50 crit will not affect your full thrust damage. This will lead you to similar full thrust damages between people despite better gear as DRG bis stat weight wise has a lot more crit and skillspeed than det.