I thought about going the WordPress theme route about a year ago and stumbled upon these same statistics. At first it seemed like a great idea. I mean, I already knew how to build them since I use WordPress for almost all my client projects.
But then I realized that part of why I was bored freelancing is that building a WordPress theme is essentially doing the same thing over and over and over again. It's just like an assembly line, factory job.
These days I'm much happier working a salary job for a company on a large scale project that is constantly getting new features and presenting fresh engineering challenges. The salary is good. I'm not a millionaire, but at least I enjoy what I spend 8-10 hours of my day doing.
https://rawgithub.com/philipwalton/html-inspector/master/dis...