Why would I spend an hour on buiding a diagram to generate code if I can type the same code in five minutes? I can read both. This is from real world experience with Rational tools.
I suspect the idea was to lower the skill ceiling to make it accessible to non-programmers or more cynically in a belief it would cut labor costs. It doesn't work out that way but overspeccing the wrong details is a persistent temptation, perhaps related to psychology of the leaders for reasons similar to micromanaging.
