not all, but maybe some of it. Because they want their bounty hunters to hold those token because maybe after bounty program, there will be holders airdrop and can boost their token because some of investors will invest of that token so that they can avail the holders airdrop.
What you are saying is meaningless, why they will do this then their ICO is finished and they will work on their project and not for this shit.
Ya it is true that in 2018 almost out of 10 coins only 3 or 4 coins get listed, some just run away and scan and some are working on their projects and they have clearly mentioned of listing after long term.