Here is why the bits don't come out. (someday we will offer it as an option)
1. It requires more complicated machining and I need funding before exploring things outside the core concept.
2. The tool was designed to be more similar to a 3-way wrench than a magnetic screwdriver. If given a choice would you prefer a fixed screwdriver (i.e. not changeable) or a magnetic tip screwdriver...which would you chose? I have asked that to dozens of people and am still waiting for someone to say the magnetic...
3. No moving parts.