Bounty hunters can quit already joining ICO projects for various reasons.
If already during the ICO, especially in the first half of the campaign, I hear that the ICO team is going to conduct a KYC check, I usually leave this project.
If I see that the table is not filled out and no shares are entered, this can also be a reason for leaving.
Also, if the ICO team changes the conditions for participation in the ICO project for the worse, sometimes this can also be the reason for this withdrawal.
In general, the reasons may be very different.