It usually surprise me when I see investors complaining about a good project that didn't increase  or providing returns immediately it got listed on the exchange and they term it scam or say different things like rekted.
But the truth is, are these investors investing in the project because they believe in it or are they just in it for the immediate profit and move on?  Because if you are investing in a project because you believe in it then you should be willing to HODL the tokens and wait for the team to gradually deliver the project and meet its necessary roadmap before you judge it and not condemn it on its first listing.