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.
This is typically true for 80% of all new coins to launch, project legitimacy, how "good" it is and various of other factors are directly correlated with how much profit they bring investors. While crypto markets are a good sign of how successful a project is, it isn't the be-all end-all consideration for how successful a project is currently or can be.
But regardless, if a project is failing on the markets, it typically is for good reasons; generally, how they executed on the launch of their coin and what exchanges/strategies that have immediately after distribution of coins and years to come. If projects have high goals post-sale that can be reasonably met with good solid evidence of how the teams execute and still drop, then yes you're 100% correct. If teams are executing and are meeting all deadlines and visions they set out with, then their failures are on how effective their marketing team is.
Almost all the time, it's due to poor execution and lack of understanding behind crypto teams. More importantly, there are only a few select exchanges that are even still operating on a profit or have actually real traders/users behind their platform, an added typical factor most seek out, what is the exchange?
Ultimately, there are many many factors to consider the successes and failures of projects, leading up to the finalization/listing to continued and ongoing development. As expressed, if a coin has been existing for several months without any crypto "pump," then their marketing and communication team is a failure. If the project is not succeeding in returning a profit (in the business) or not acquiring adoption/integration, then that crypto is a failure. If a coin dumps immediately after exchange listings, then it is all summed up above.