By the same logic what is the point of only giving jobs Protect II when the highest tier is V. Come on, get real. Changing the weather is one of the few unique spells they have left now SE have given their triggers away. Personally I don't think any job should get storm spells other than SCH and they should have been blocked or the levels put higher.
The only reason you want it is for SMN's suit and quite frankly that is a lol reason. What's next "Aurorastorm/Voidstorm I can has this"
Jobs /SCH get the bonus of "SOME" storm spells, this is the was it works for ALL jobs. You get some of their abilities, but NOT all of 'em.