Because you do not want to divulge how much you are earning, you can be called greedy, there are a lot of bounty hunters who are working all year long and they happen to be victims of scam projects and they are getting nothing at all, your friend's word is true so many projects are a total waste of time.
I am not sure that anyone will call those who keep the amount of their income secret a greedy one, it is when people start to mislead and manipulate the others that you call them greedy and I vividly understand what he is trying to say.
We have some people that are still participating in a very good project and instead of them to let others knows project they are participating in and reason why they believe they are cool based on their own research, they will continue to just come on the forum to mislead people by telling them that all projects are scam so that there can be less participation in the number of hunters, and you know that the lesser the participants, the higher the number of token that will be allocated to those who participated.