I think the problem here is that.
1) tea was meant to be steeped - whether that is loose (in a teaball) or in tea bag, it does not matter. The taste does not change.
2) Coco Mix is the standard for making coco now-a-days. Since no one melts chocolate, adds sugar & cream and stirs for the next 1/2 hour - people don't mind buying instant coco
3) Coffee on the other hand tastes very different when it is brewed, as compared to instant.
I'm just not sure if real coffee drinkers are willing to spend the money on instant coffee. That said, if you package something cute enough - people will buy almost anything. LOL