I didn't mean to imply that stock markets were not important, just that "allocating resources" in the sense that parent meant, e.g. "How many people does a company making spoons gets to hire or should we put more of them on webforum moderation ?", being its primary purpose seems like a stretch (except for the occasional new IPO / stockholders' meeting). If anything, venture capital and as you mentioned, debt markets are closer to this idea of allocating resources.
My main point really was that the examples parent gave seemed much closer to examples of market economics in general and would hold true, with or without stock markets.
I can see the limitations in equating stock price directly with GM retooling a factory for a new model year, but it is a far more accurate depiction of what is going on, even if a little abstract, than to say that they have nothing to do with each other and even spelling it out letter by letter. Saying that it is basically a closed system is even more bizarre.
My main point really was that the examples parent gave seemed much closer to examples of market economics in general and would hold true, with or without stock markets.