8 people per Starship (which you have not justified, given its 100-150 tons to LEO design and refuelling in LEO for such missions and the 1000m^3 interior volume; I’ve shared a 70m^3 apartment with another person comfortably for longer than the trip duration, and that’s 14 such units and 28 people in the same volume, and my university accommodation was much denser even than that, so what machinery fraction do you imagine?), and let’s say they can transit one way on each conjunction even though that’s probably only true for the first few trips before fuel generation and storage is done reliably prior to arrival, is still 200 per vehicle-in-the-fleet per century, or million people in a century with a fleet of 5000 Starship-equivalent vehicles. Which is a lot of Starships, but there are more 737s, so it’s not like aerospace can’t be built at this scale.
Now, criticism of Musk’s target price per seat given your beliefs of the maximum occupancy per vehicle to Mars, that would make more sense.
As would arguing that once you have Starship as a launch vehicle, it would make more sense to use it to build some Aldrin cyclers rather than use Starship for everything.
Oh, and we may ban it from operation at that scale because of the environmental concerns. That’s certainly possible.
But that’s not what it looks like you’re doing, it looks like you’re saying it can’t rather than it will be too expensive or that its mere existence creates better solutions or it might be held back for legal reasons.