Why are there no multi-hit skills on Sage?

[Allegor]

I guess that's just where opinions differ, I find Kardia to be extremely lacking, not necessarily it's potency but it's utilization as a mechanic.

What does Kardia currently do? It heals a single player for a single instance of 170 potency every time you cast a damage spell and it can be buffed for 4 casts with Soteria, that is literally all the interaction it has with Sage's healing kit.

What people are asking for is to make Kardia a more integral mechanic for the job, so instead of 10 different oGCDs that all "just heal by X potency" you get more options to interact with Kardia as a healing mechanic.

As an example let's say instead of Druochole's flat 600 potency healing you get a multi-hit spell that procs 3-4 instances of Kardia or instead of Ixochole you get an ability that spreads Kardia to the entire party for the next 2-3 attacks you do.

Pretty much this. Kardia is SGE's identity, like cards are to AST or the fairy to SCH, it should be the job's core mechanic, not just a Regen/Embrace clone