Unlikely, the more people are involved, the more spam on the social networks and that is what they want, their ico will be for many people.
The purpose of bounty is to makerting and the more participants they promote success
Totaly agree with you, but a few days ago I had the conversation with bounty manager and he said that they don`t want a lot of spam in social networks. So they limited number of participants and made hard rules for own posts. This is good strategy also - they will receive only constructive posts and comments.