Explaining your design work is part of your design work. It’s the same with web development. It’s our job to explain how the web works… and how the unevenly-distributed nature of browser capabilities is not a bug, it’s a feature.
Jeremy ends by saying:
The web is not a platform. It’s a continuum.
How I’ve explained it in my responsive design workshops is like this.
The web’s a river. It starts off narrow up in the mountains and gets wider and wider as it nears the sea, and you can never know at what point people will want to cross.