I generally think it's a cup half empty vs half full situation. If I buy small amounts via an exchange, and immediately spend to a mint, then at least things stay consistent. If I buy small amounts kyc free, I could be buying from a known criminal. That could look even more shady. Also, why do I need buying bitcoin to be kept a secret? As long as the coins lead to a mint and disappear, what's the diff? Buying bitcoin is not a crime.