We can not blame the projects for not being listed. First of all, they have their own roadmap, and we should support them if the market situation is not appropriate for listing.
A lot of these bounty projects take time to enter the market because they have a process they have to follow through, I guess. Most of these exchanges, especially the top rated ones would not like to list just any coin on their site. And again, I totally agree with the fact that they might be trying to avoid the massive dumps that usually come after the airdrops.
Bounty is free marketing. Because almost all of the projects pay with their own tokens. Since the Tokens are in their own hands, they advertise their products for free.
Most projects say they will distribute token worth $ 500,000. But the actual average is the distribution of token worth $ 50,000. If we're optimistic.
Therefore, almost no project wants to miss this opportunity.
In fact, I do'nt think it is free if developers value their coins. We can not think of the opposite, at least considering the money invested for the project. Many projects evaluate their coins more valuable, and instead pay rewards with ETH.