True.
Its hard to judge because there hasn't been anything like this since the dotcom bubble in the 90's
I believe it was about five or six years before everything started to fall apart (1994 to just after 2000 before a lot of big companies went bankrupt)
maybe someone can provide a more accurate timeline on this.
but the dotcom bubble was based on actual functioning companies, even if they were crappy ones. they had employees, products, services, serious investors and even customers and actual utility. that all takes real time to screw up and die.
icos are dust built on even more dust. their 'bedrocks' are nothing than speculative playthings, let alone their ico offshoots. even bitcoin has a long, long way to go before it's anything more than speculation.
Dotcom companies went down because there were too many of them offering things there wasn't a big market for. ICOs may not go this way because the main thing they deal with - their foundation is simply human greed, and you can count on that to go on and on. Just look around and ask yourself why are there still casinos and gambling halls when we all know they're just a legal way for robbing people.