Hello,

It's an understandable request when reviewing the magic weakness triggering percentages compared to job abilities and weapon skills. The order of proc rates is definitely magic > abilities > WS in order from lowest to highest, so magic is the low end.
The reason why magic proc rate was set at a lower value is because weapon skills require TP, and since they cannot be quickly used over and over again in a single battle we set the activation rate higher. Spells on the other hand have a quick casting time and can be reused at a much faster pace. Therefore, the weakness triggering rate is set lower since the amount of times you can cast is considerably faster. (Abilities are 30 seconds to a couple minutes, so this is in the middle)

We've made adjustments so that the procs occur at their expected values, but since magic spells can be used quickly, there is a remaining impression that weaknesses cannot be exploited.