Nowadays is popular to ask kyc but that isn't the reason.
the ONLY reason why they started asking for KYC was because ICOs started failing at some point and started falling apart. so they had to do something to keep it alive a little longer while add an additional method of making some extra money.
so they added KYC to
look legit while they continue scamming people and then on top of it they sold all the KYC data on black market and make extra money from it.