The goal of keeping the market competitive has to trump the goal of each individual corporation to eliminate its competitors, just as in ecosystems, the goal of keeping populations in balance and evolving has to trump the goal of each population to reproduce without limit.
That sets up am interesting question. Seemingly these are similar situations but for one it's easier to see how human agency in setting goals is relevant. For the other, an ecosystem can easily function completely without humans as well, and has generally sustained competition and dynamic stability (allostasis)
