Marketplace competition and non-zero-sumness are not mutually exclusive, at least not if you are a capitalist. The total money spent on spaceflight will be larger with both companies in the market than with either one alone, therefore it is not a zero-sum game.<p>As for acknowledging each others advancements - you don&#x27;t see Sony or Dell going out of their way to mention Apple, for obvious reasons. This is normal behavior between competitors. I don&#x27;t see why people are making so much out of Bezos&#x27; tweet; it was just a stupid joke.