No one will ever use Coinbase or something similar to host ICO's, because ICO's have been working fine without them. Not to mention, Coinbase has the SEC right up their bums, and i doubt some of these shady motherfuckers in digital currencies would ever want anything to do with them.
Who remembers Moolah? good times
This. Coinbase also has the IRS demanding to see all their member accounts (they've successfully resisted, but for how long?).
Lots of the ICO operators are shady and don't want teh scruitiny an account with coinbase would bring.