Recently I had to let someone go because the "fit" wasn't quite right. This is not something I want to do again any time soon.
Employing someone who is not passionate or at least interested in their position may effect the morale and dynamic of the rest of the team. This is especially true in a small business.
In the past I've seen potential in everyone that has worked for my company. No one is perfect, but some things really count more than others. Enthusiasm, experience and dedication goes a long way to creating a great atmosphere in a small business working environment.