Very often tokens appear on the exchanges only for speculation. The product is not ready and there is no need in the tokens on the platform because it is not ready.
Exactly. The team creates a project "sold and forgotten." I would not be surprised if it turns out that there are teams that have done dozens of ICO and have cheat many people out of their money.
I think that now the times change a little bit. It became more difficult to create a "sold and forgotten" projects.