The best place to promote your capabilities as a Drupal developer and themer is at Drupal.org. Yes, maybe it was irrelevant to make money from open source software such as Drupal, but what we sell is our time.
We get paid to create a custom module, custom theme or creating a site and it requires quite a long time depending on how hard would it, and time is money right? :)
If calculated, more profitable to make a theme or a Drupal website instead of making free software that I have done in the past. I have a free software that has quite a lot of users but only a few people who want to donate.
That is why I am now also elaborates Drupal. Of course I also still pursue the software development, but for now I am relying on Drupal to make money.