Security. While many other exchanges have been hacked or simply walked away with users' money, coinbase is one of the oldest that is still around, and has rema

Security. While many other exchanges have been hacked or simply walked away with users' money, coinbase is one of the oldest that is still around, and has remained professional and secure throughout. They refused to support various blockchains until they were sure they could do it securely and reliably. In a way it's somewhat poetic, as they sell trust for a trustless ecosystem.