Are flags really meant to reduce the expected rewards if you personally consider them to be too big?
If so, I'd have to tag every third post from every third whale. A picture of eating, a good morning, a short story about how you took your child to kindergarten and a payout of 50$+.......
I have always found that unfair, but the flags are not meant for that.
I also believe that flags are noticeably reducing their own reputation. In addition, you can mark an infinite number of VPs because you don't lose any VPs.
In summary, my opinion is that there are enough people who get too much money for their posts, but flagging is not meant for that. When I get a flag, I want to know why and a "my opinion is you get too much payout" is not a real reason.