Interesting question and never hits on my mind. We are now seeing huge sufferings from ICO last year and up until today since Bitcoin went down up to $3000. Every altcoins are following the bitcoin price movement so as the investors. I never observe ICOs when bitcoin was under $1000 but I could say that their era is now on the verge of death so I am pretty sure that this ICO scheme will be vanish if bitcoin falls below $1000. These ICO actually ruined the momentum of bitcoin.
That's right after Bitcoin lost its price to under $ 100 ICO experienced critical conditions most of the Altcoin projects failed and added Scammers. Sometimes we often forget or don't immediately notice this vast Crypto Space and that almost happens to everyone, Bitcoin is the biggest and most expensive currency so if the price goes down, there will certainly be many investors who have difficulty developing their projects. ICO can come back to life after an increase.