That's fine. Your bank doesn't pretend to be decentralized. Cryptocurrencies do. And in doing so, shift the responsibility of safeguarding the keys to the user.
It was regarding the 'regulation' thing. Cryptocurrency is only ever going to work for John Everyman if the industry starts to mature a bit. Blaming the user when another exchange gets ripped off doesn't exactly scream 'legit', does it?
I'm not sure it's meaningful to say cryptocurrencies are decentralized. Decentralization is more of a social phenomenon than technical, e.g. cash is decentralized but socially we've found advantages to centralize.