Kind of sounds like a few ends up being every one? I don;t think a few people will have that effect. Then again, it depends on your definition of a few lol
It's a domino effect.
For simplicity sake, lets take this example: There are 150 players in blue when suddenly, orange uncaps itself.
Group 1: 20% of players in blue will always go to orange no matter what
Group 2: 20% of players will stay in blue as long as there are >130 players
Group 3: 20% of players will stay in blue as long as there are >100 players
Group 4: 30% will only leave if there are less than 75 players
Group 5: 10% are afk/toolshedding/whatever and will stay indefinitely
So after Group 1 leaves you are left with 120 players.
Well now Group 2 is going to leave because this is <130.
Now you are sitting at 90 players. Well, Group 3 is going to leave now because you are less than 100.
Now you have 70 players. Group 4 is going to leave now.
So now you are left with 15.
Is it group 2's fault that group 1 bolted for the door? Is it group 3's fault group 2 bolted? Group 4, the most accepting to play in a small arena has had enough when the others bolt. Is it their fault? Domino effect my friends.