Lua was created as a configuration language and it is excellent as a way to store data, but JSON has a much wider use.
Come on! This really comes across as very rude. What do you expect will happen when you write “fix it”? That we drop everything we are working on and make this our top priority?
JSON is not a scripting language like Lua is. JSON is a data container format. We use JSON in our projects to hold some kinds of data such as localization or definitions (and use the mentioned json.lua to interact with JSON files), but I prefer using Lua tables when I can. When you use sys.save() or sys.load() you are saving/loading directly to Lua tables.
I tend to favour lua over json. They are more or less the same.
I have run into a situation where I had to use json, because I had more than 27000 entries, and for some reason that was crashing the html5 build (not the desktop or mobile). Converted to json and it was working on all the platforms with no issues. This is another story though