There are a lot of scam projects now, but 80% too much to give ICO scam value, I more agree 50% for ICO scam, because there are a lot of ICOs out there that are nice and keep developing their project up to now
I think 50% is a reasonable rate, some ICOs are not scamming, they still grow as their Roadmap, but the price of the coin drop hard when being listed in the exchanges make the investors feel like they get scammed.