"Ulterior motives" is misleading terminology, trying to give a negative color to ambitions that Elon has always made very very explicit—making humans a space-faring civilization and colonizing Mars.
You may disagree with how useful these ambitions are, but calling them ulterior is basically outright deception.
You are free to disagree with them. For what it's worth I think they are genuine. But either way they have been very clearly and explicitly communicated, and are anything but "ulterior".
Loss of a competitor might change its pricing structure, but they want success for reasons that go beyond extracting money.