this is the mistake you are making which leads to your confusion about altcoin price dumps and you think it is some sort of cheating behind the scene by some malicious person killing the "good project".
the reality is that the projects are shitty. at least 95% of the altcoins have no reason to exist but they do. so obviously they have to die. and that is exactly what's happening. they lose value and slowly die. so in other words what you see and are confused about is a very natural thing in this market.