Neither software nor architecture are easy to understand. The wall example is similar to "Write a simple calculator capable of doing addition, substraction, di

Neither software nor architecture are easy to understand. The wall example is similar to "Write a simple calculator capable of doing addition, substraction, division and multiplication". Anyone can tell if that software works as expected or not and have some idea if it's well done or not. A similar comparison would be a team designing and building a fully functional house on a budget. In that example it's not easy at all to assert how well they are working, as happens in software development.