It's harder for people to cheat because they have paint on them. Some people are known to take gloves off if they get hit. In airsoft you get those bad lemons that get shot ten times and wont yell hit.
Also their is the demographic factor. In my opinion airsoft appeals more towards those who play tons of Call of Duty, young kids, and the gamer culture. Where I live I see more athletic people play paintball, and in Airsoft I see a ton of pudgy kids.