I'm a CA native myself, and I don't talk the same way I write. In person, I probably would have said something like "but you're assuming away the key legal test, which is 'what is the "relevant market?"'". I tend to not go back and edit my comments for style, just for clarity. Could it be more polite? I guess, but it also seems pretty consistent with the logical/syllogistic style that is common on HN.

I thought the question was not entirely in good faith, since it would be pretty obvious that there's no such thing as "monopoly on X" — otherwise it would make Sony a monopolist on Playstation, Microsoft a monopolist on XBox, etc.