Thanks for the comment Hyroen,
I think of Thunderstorm and Lightning Storm as a weaker, under-appreciated CC and this is a way of encouraging its use. I think of the name of this passive skill to be something like Surge or Charge. You know, the air gets charged with the storm incoming, and Sapphire Stone/Gem is able to harness that. Let me know what you think, if I'm off the mark here.
As for the ability, Air is about about its versatility with things like Dive and just its nature, so it was another way for Air to become more efficient.
Let me know.