Reasons of red tags
1) Join and support scam projects;
Promoting a project which turns out to be scam is not worthy of a red trust (this is my opinion), except it can be proven that the user had information about the scam, or found out at a later time and did not expose the developers.
It's possible to unknowingly enter a promotion campaign for a scam project.
I disagree, we all have to take responsibility for our actions and this includes researching schemes before promoting them in exchange for payment.
"But I didn't know they were a scam" usually is more accurately written as "I didn't care if they were a scam, I just wanted the money."