I don't know what the argument is for that. Maybe that sim training will be a larger percentage of training in the future, and therefore operating costs don't matter so much? Take whatever jet has the best capabilities, period?

I think what that misses is that maintenance of real aircraft will atrophy without constant pilot feedback. Of course mechanics can follow the maintenance guidelines, but so much of that, historically, is guided, modified, and improved by experience from wear and tear from actual use.