I am not sure what you are objecting to: The idea that customers don't have firmly stated requirements when they sign an outsourcing contract? The idea that good contractors should work with customers to clarify, elaborate, and refine requirements, resolving conflicts between stated requirements when they occur? The idea that contractors shouldn't blame the customer if they don't get a sufficiently complete set of requirements? The idea that an MVP can be deployed to help advance the overall contract's progress?
Conflicting requirements are a different problem than being unable to provide requirements (or articulate them correctly). It's lucky when a customer empowers exactly one person (at least for a given scope) to resolve such conflicts. More often, for the political reasons you mention, the customer wants to have too many cooks, and they spoil the requirements soup.