You do raise a good point. But there are still the people who just want to add a civ, change unit stat, make a simple scenario. Why do these people have to go to the trouble of learning a programming language just to make one or two little tweaks?
You do not need to learn a programming language to do so.
Yes, but it can look quite overwhelming, with all these short-form tags, "i" at the beginning of some tags, "b" at the beginning of others. More complicated than simply opening a window and changing a text box from "15" to "16" or using a scroll menu to change a prerequisite from bronze working to iron working.
Once you have done it a few times (2 or 3) it comes natural, I agree the learnign curve is steeper, but it also offers more flexibility.
If you never did it because it felt too complicated, you never realized how easy it is.