> Except that in the case of CDG they decided that it's not enough to be able to make the trip within 2h30 from Paris, you need to be able to do so from the TGV station at CDG airport. That's absurd, the vast majority of flights from CDG are from passengers in Paris, not passengers that start at CDG airport.

Doing so would ban connecting flights.

Imagine instead of just going to the connecting terminal if you had to leave the airport, grab all your stuff, go into a local train, then to the train-station...