There has to be Global Regulatory Authority which all ICOs or crypto related project must pass due diligence test before even commencing any form of bounty and token sales.
Don't you think that the so called Global Regulatory Authority will then eventually take away the concept of decentralization ?
Only the people from the GRA will be able to pass an ICO which means it will be a centralized authority.
Also, it doesn't mean that if a GRA has approved an ICO to be launched it won't scam the people. The ICO can still scam the people anyway.