The nice thing about hiring from an Open Source community is that it makes the hiring process significantly easier. I've been working with Gabor and Kieran for many years, so I knew exactly what to expect in terms of their capabilities, the quality of their work, and even their shortcomings. Needless to say, I like Gabor and Kieran a great deal -- both have been instrumental in the success of Drupal.
Developers whose experience is mostly with traditional closed-source software companies may, or may not, have the right attitude towards how to work with an Open Source community, and the Drupal community in particular. We don't want to grab; we want to give. What is important here is that Gabor and Kieran understand Open Source development, and how we gain by giving. Acquia succeeds if we work closely with the community to advance Drupal. By hiring Gabor and Kieran, we make sure we are staffing the company with people who want to be strong contributors to make Drupal better.