Yeah great, show your proprietary code to a third party company and everyone is just going to immediately trust you.
Plenty of other cloud storage services offer real reasons to trust the backing store, called the code is open. I can audit it, my neighbor could audit it, and every corporate user is liable to audit it. I have no reason to ever trust an arbitrary third party I have never had reason to trust in the past who is now trying to guarantee your cloud is secure, when competitive options are letting me do my own auditing, if I wish.
Is there anything else this is comparable too - where a company has the gall to say "another company looked at our black box and said it was good, so trust us alright guys?". When cars or houses or roads or food get certified for something you always have the capacity to reproduce the certification process yourself as a verification measure. You cannot do that to proprietary software, especially when its on some foreign server somewhere running who knows what version of it.