Why passive income? When you participate in bounty campaign, you make the day-to-day work. I think passive income is more like money received regularly without effort.
Passive income is investing money and watching how your investments grow, but you still need to monitor news and etc. Bounty is like a real job when you need to be active every day and have good discipline
You're right. Plus, if you take into account the drop in revenue from bounty campaigns, then we can say that the intensity of this work is constantly growing. And efficiency unfortunately falls.