How do you know any of that is true?
For a customer you can easily have a tour arranged. You can meet with your account manager regularly. You'll know the people assigned to your account.... Your agent can just tell you since we all go on tours.
A tour. Is this middle-school? Sure, a tour is nice and fun... and always gives you a good impression, because that's that tours are for. Lets be honest, no company would allow, let alone offer, tours if it had any risk of leaving a bad impression to potential customer. But if you are touring through a corporate Disney park, that they won't say.
The only way to verify what the previous poster addresses, is through regular audits covering all facets of production, management, troubleshooting, etc. You need to talk to those workers, that the provider will not put in front of the customer during the touristic tour. You need to review their experience, work methods, communications methods and so on. No company in the world would allow a client to perform such audits, except maybe if the client is ESA or the USAF or something like that.
And now we are speaking only about competence. Whether the provider plays (willingly or not) hand it hand with intelligence agencies is yet another question, one you will never find the answer to unless there's another leak. But you can probably bet your ass that every god damned intelligence agency is either deep within your cloud provider or trying to get there. From the NSA to North Korea, with China, Russia and Isreal. They are all there, waiting for your sensitive data. What else do you expect when you concentrate data in large data centers which are fully accessible in the open world?
You obviously still like bedtime stories. In the meanwhile, I'll leave my sensitive data off the hands of cloud.