It's fairly obvious that there are going to be more people that are right-handed than there are people who are left-handed.
If I'm not mistaken, right-handedness is not only a dominant gene but also the "standard" as accepted by most societies. Example: Someone might be technically stronger in their left hand, but they may well have been brought up to use their right hand as their "primary" hand.
I'm left-handed, but I use a mouse with my right.