I was considering adding a scripting language to a bespoke game engine of mine. There were lots of small, one-off style things especially surrounding narrative based events. These could've been driven with data, but what I was really describing was logic. I felt that it didn't make sense to do that.
I took a look at the prior art. Bethesda has two different scripting languages that they use in their custom engines, and Blizzard used Lua for UI and quests in WoW.
Still, driving things with data can work very well. I decided to try to make an engine for narrative only games -- virtual novels -- and see how well it worked. Quickly, I found I wasn't happy with the way things were coming together, and abandoned the project. What's left can be found here, but the code is likely of little import; the lesson to be learned is something you may find to be of more value.