You are thinking is perfect. This is the way bounty programs shovel be working today also. With the increasing number of participation increases the number of dumpers when the coin get listed! This reduces the token economy badly and thus makes it worse.

Also it doesn't matter if there are 5K participants or 1 ml participants as long as they are scammers then whats the use of spending so much money?

Instead of that they shovel be spending their money on the real development of project and increase the value of coins!