Earlier quoted context omitted.
Presumably the argument is that a storage host might dutifully provide proofs of storage, but refuse to actually transfer your data to you later. This is true, but it's also true of centralized storage providers. The difference is that traditional providers are typically bound by SLAs -- something that a blockchain can't really offer. Instead, decentralized storage gives you the ability to store your data with dozens…
Sure it can provide an SLA. The code is the SLA. And is available for all to examine. Via opensource. And governance allows the community to change terms/accept code... moving forward.
It's not _likely_, as that would negate the usefulness of the whole system if it became an issue, and therefore negate the cash flow into the system.
Ultimately what's keeping the storage providers honest, whether they're centralized or decentralized, is that their future profit stream is based on their current behavior, and they presumably care about future profits. Code and SLAs ain't nothing but words.