yes, they are a lot of projects that are dead, even after the ico was finished they left their project already..
Yeah this is the case of scam project.
Another ones completed to develop it and disappeared.
I cannot count the times I was scammed during the bounties.
Recently russian team of Sint disappeared. Ubiatar is a notte example!
this is a risk that we must accept sincerely because this is not a rare thing because only a few percent of many projects are living and developing.
so we really have to be careful if you want to invest in Crypto.