Broadly, you have a point. However with Tesla Musk has been pretty consistent that they would be directly doing it and they have the Tesla app managing the rides.

Their strategy has been all in one, they make the cars, they own the chargers, and they don’t really partner with anyone in any significant way.

While it does happen that companies end up partnering and competing at the same time, it’s relatively less likely. So for Tesla it is extra strange to be pitching being a supplier for other autonomous taxis while simultaneously being in the market.

So yeah, generally it is a poor argument, but in the context of Tesla, it is at least a bit out of character for them.