There are several ways to get bitcoin without revealing your real identity. Coinbase has limits to withdrawals capping at .08 BTC per week. From the point of withdrawal your coins will be tied to your identity and can be tracked unless thoroughly mixed(which costs fees). Also there's the ick factor that they promote shitcoins, work with the central banks and US Gov regulators, and hold Blackrock, fidelity, and other ETF coins which makes them a hacker's honey pot.