Because after ICO Tokens Can be buy anyone without submitting any KYC
Totally confusing this process

The reason why ICO's are requiring KYC is because when they register to launch their coin the Securities and Exchange are requiring them to comply with KYC and AML regulations. Thus they are asking people to comply with the requirements but after the ICO when their coins entered the exchange KYC is no longer needed. But if you buy at their website KYC is still required.