Quote:
"for that specific society/culture in that specific time and place;"

society/culture of Jews = Chosen by God to spread His laws (Torah) throughout the world to all nations, so that all humans would recognize HaShem and obey His laws of justice.

society/culture of the seven nations = Refused to follow even the most basic laws of civilized nations. Promoted murder, theft, animal sexual abuse, cruelty and injustice of all sorts. Irrevocably evil and would have inevitably spread their evil throughout all other peoples including the Jews.

specific time and place = see below



Quote:
"the severe, practical limitations of a long ago time and place."

"Severe, practical limitations" due to time and place, not due to Torah. Refers to lack of those modern technological advances that - one may argue - might have made it plausible or at least remotely possible (without guarantee) to defeat, subdue, and contain a truly evil society/culture so that rehabilitation and reformation might have been possible while - at the same time - protecting those who did admit obligation to 7 laws of Noah (the minimal level of decent and civilized behavior).

The severe, practical limitations of that long ago time and place make this argument moot. There was no alternative but to eliminate a truly evil society/culture.