"does the fact that mr. crocodile eats small, flightless birds invalidate his argument that he can get me (a small, flightless bird) across the river faster than i could do so alone?"
I didn't say 'show me an example of how motivations can invalidate an argument', I am talking about this particular example - how does Epic et al's desire to make money invalidate their argument that Apple has a anti-competitive monopoly on the app store?