Very good arguments!
Excellent !
I'd add that even astronauts on another world cannot (inspite of their ingenuity, capacity to improvise) always fix everything (are all the tools available?) or discover something a robot can't (even Schmitt made mistakes while on the Moon).
Robots will keep getting smaller, better, cheaper while humans will keep needing this much mass and that much volume.
And if the real reason to go to Mars is to inhabit it (meaning living separately from the Earth), then no government will help them do something for which it expects not to get rewarded.