Jason Brennan argues that language can be used as an example by which we can judge the moral consequences of a spontaneous order. His argument is to suppose that a language "through no fault of their own" results in some speakers of a language being poorer than others. Since we can't control the language that we speak, the spontaneous order of language is morally blameable.
The tacit assumption is that language constrains how we think and therefore how we act. It is also the assumption in the paper that Brennan links to, which is critiqued by linguists here and here. What if, as Steven Pinker argues in The Stuff of Thought, how we act also determines how we speak, our language? Then language is no longer a constraint on our thinking. The relationship between how we act and how we speak and think is bi-directional. Yes, the habits of language are habits, but our minds are not constrained by the habits of language so that we can pinpoint language as morally blameworthy. The spontaneous order of an institution does not predetermine our thinking any more than the spontaneous order of the mind predetermines our external institutions. Both are plastic, to varying degrees, and feedback on each other.