Very interesting read, especially the mention of salary numbers. I had been wondering about those in absolute terms as well as the TV comparison for a while.
I work in the software industry, which I speculate is actually not that dissimilar from novel writing in terms of the work experience (you sit a lot, a lot of the work process is ultimately solitary, work doesn't really stop when you get up but rather a lot of the difficult problems tend to get solved away from the desk in your head, you need to juggle different levels of complexity both localized and global to the project in front of you, high levels of concentration are required for hours on end to be productive, etc.) and we definitely tend to get paid much better.
Worth keeping in mind when considering book pricing.