it is difficult to establish what is a scam and will not but we must be more precise in choosing the bounty to be followed,
many things must be learned from the platform whether or not convincing by looking at the team that handles and clear or not the project to run
it all depends on the organizers if indeed from the beginning they have planned fraud then it is a scam
You are right, even ICO rating gives no guarantee that ICO is not a scam. But even if it is difficult, some smart and kind people always inform you if there is a suspicious project, you can find the information here
Scam Accusations. Being stuck with a scam bounty project is a risk, almost everyone is experiencing it, so take it even harder and do not be sad.