Honestly speaking I am quite surprised that is still so common in the UAE. I always thought that it's a thing of the past. Among the people I know personally, I have not heard about anyone who does not hold his/her own passport.
Entisar, you're the first person in my knowledge who's passport is held by his company. I'm assuming it's only local Emirati companies who do that and not MNCs. Most of the people I know, do work for MNCs. That's why I might not have been aware of this practice still being so widespread.