It's not dissimilar to the way food recipe books work.
Creating a dish, replicating the dish, writing a recipe, getting competent cooks to follow the recipe, getting non-competant cooks to follow it, and so on. [1]
It all leads to multiple revisions and takes a lot of time.
And this is for -food-. Imagine doing it for something a lot less tolerant of variation.
[1] old recipes start with "pluck 2 chickens" because, you know, someone followed the recipe and didn't pluck the chickens...
Creating a dish, replicating the dish, writing a recipe, getting competent cooks to follow the recipe, getting non-competant cooks to follow it, and so on. [1]
It all leads to multiple revisions and takes a lot of time.
And this is for -food-. Imagine doing it for something a lot less tolerant of variation.
[1] old recipes start with "pluck 2 chickens" because, you know, someone followed the recipe and didn't pluck the chickens...