There are a huge number of Bounty Campaign. A very large number of projects. But I like your remark very well. It's a bit of a way to get diversified until one ends up paying.
This is the strategy of most bounty hunters that remain faithful to bounty hunting and still trying their best to find luck with it. They keep joining bounties until they end up with the one that's true and going to pay their efforts.
In regards to hunters, i do not think dump off is what is actually done.
Bounty tokens are sold for value, not dumped.
It is not only the bounty hunters that are dumping and selling what's being determined as it's price. Include also the investors because they knew it that a massive sell off will come once a token gets into exchanges.