there are legit ico from the start and from the middle but sometimes thier coin can become a deadcoin because investors are not interested on them anymore .
investors do also want new from time to time and they go for newer projects and then jump again from the other .
its not also the fault of investors but sometimes its the developer of the coin because they dont improve their coins anymore or they already forgot their plans for thier project .
From what I have seen, the vast majority of the ICOs do have very good ideas and planning. The investors get attracted by all this and they pour their hard earned money in to these projects. But once the team gets rich from this money, the development gets a lower priority and in many cases the project becomes dormant. The tokens will start losing their value and in a few months they can lose more than 90% of their exchange rate. Eventually, the tokens will become dormant and they will no longer be actively traded.
The only solution to this, is not to allow any project where the development is not even 50% complete. Nowadays, a lot many of the ICOs go to the market even before the development is started. All they have is a nice white paper, an idea and in some cases a beautifully designed website. Such instances can't be allowed any further. If we want to remove the scam projects, then only those in the later stages of development should be allowed. Else, the funds should be kept in escrow and released only when the project milestones are complete.