I dont think its going to happen nearest few years, I think ICOs will evolve, and bounty campaigns as well. And as a result ICOs will become less in quantity and better in quality.
It only come to an end if crypto won't give anything to us or nothing have build investment into crypto. But I never think is just an easy happen since a lot of people are started to cultivate and make gains from here. Definitely, it will spread more than of lessening it's popularity.