I never considered bounty as the main job. with many ico popping up, not all ico give honest bounty jobs in payments. and not all ico successfully reach their hardcaps. in my opinion there is no certainty of payment in every job. just imagine if you work as a bounties signature and have worked for months and it turns out that the bounty you are working on failed to reach hardcaps or just another ico scam. and you don't get anything.. trust me.
Yeah most of the time bounties failed and the tokens we earned will only give us few profits, but it will still depends on how successful the project will be and what strategies we will be using.