It's a cycle, so whenever a new project pops everyone would like to see and look for the decency and legitimacy of the project. And if they think that it's quite good enough for them, they'll look after the rewards and join later. I guess everybody is aware of that situation of this cycle that a new project has more chance of failing than succeeding but they keep on trying because that's all they want to do. So, no question on why they keep on promoting it but they have to be picky and choose the legit and avoid the scams.
Even you are a picky person but you can't simply find out that a certain project is legit or not cause most scammers now are smart enough to hide their intentions and looking they project, you can't feel that it was scammy one, and you can just figure it out later. Sad to know that most bounty hunters become a victim to this and waste their time promoting for nothing. It was really disappointing into their side but isn't a reason why we quit, if we keep moving and keep searching, we can finally find out best and legit projects. Huge rewards are really tempting but this is also a way to hide who really they are. We'd never look into that but rather to look inside and to find that they are promising enough.
