The answer to the question implied in the article -- why does Libra make such unjustified design decisions -- is simple. Some people have become enamored with blockchain despite it having almost no good use cases, and this certainly isn't one. It seems like a classic example of focusing on the technology rather than on the problem.
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Regardless of the other, far more important sections of this article, I find the section about the programming language misleading. Programming language theory does not study the quality of programming languages or their suitability to certain tasks. It is simply outside the purview of the discipline. PLT does not have any tools whatsoever to determine which language is more or less suitable and it is not interested in that question. The theory studies the properties of formal systems and the internal implications of their design. Much like mathematics can deduce from the Peano axioms that 10 > 5, but it says absolutely nothing about whether 10 is "better" than 5 because the answer to that depends on context (are we talking cookies or tumors?) that is simply outside the purview of mathematics. Similarly, PLT can say whether a certain formal system is sound or not, but it says nothing whatsoever about whether soundness is "good", "bad" or neutral, and certainly not how good or bad it is. Of course, programming language theorists have opinions on the matter, but those opinions are not supported by the theory.
Also, given the other glaring flaws, there is nothing to suggest that a formal definition of the programming language would improve matters in any perceptible way. After all, we do entrust the world's monetary system, and sometimes even our lives, to software written in programming languages that don't have a formal definition. As someone who studies the issue of software correctness, a formal definition of a programming language is certainly of interest to theorists, but it has not been shown to be a particularly worthwhile means of increasing correctness.