Briar Patch issue?

Maybe just an issue for me?
Set out to play a Plant Druid, watering my plants with Thunderstorm to create a full on Little Shop of Horrors.

My 1st spirit gem at Freythorn - the only choice that seems right is Briarpatch right? Storing all the lovely physical damage my plants are doing & then every 8 second, BAM! A Briarpatch explodes dealing that stored up physical damage - with a juicy 50% more damage with it being overgrown from being watered with my Thunderstorms (when I get to pick that skill up), right?

Except no... I have to be doing physical 'attack' damage in shapeshifted form? (or however else). This makes zero sense thematically? Why would a frost wearwolf or a lava wearbear use a briarpatch? It fits none of the other architypes for the other charactor types either, they have Spirit skills that already perfectly fit their needs & functions.

Surely to go all out to put plant based Spells into the game, with plant spell power nodes in the skill tree, then add a plant based Spirit Skill, they should work together, no? Briarpatch is the only Spirit skill that thematically goes with a non-shapshifting Druid.

Please could this be changed to just store Physical Damage dealt, not Physical Attack damage.