With the number of bounty hunters increasing by the day,the reward is more likely to reduce than to increase. The earlier will accept that and move on the better for everyone of us. We should understand that, crying for unrealistic rewards can make developers and teams to promised unrealistic rewards.
The lower allocation and scam projects existed in the last year are also the reason why less reward on bounty campaign. I don't think amount of bounty hunters give significant negative effect on the reward. However, campaign managers can be more selective to accept participants to make everyone happy.