A straw man would be more something like "since no one has ever seen how badly immortal societies have gone, no one can say they're bad."
I'm probably what you would describe as 'pro-death'. But I would never have made any of the arguments you listed.
I could just as easily frame your positions to suit my argument.
For example; 'More people make more progress faster.' (India has not made as large a contribution to modern technology as the USA)
Only if you take the statement as some immutable law and not the intended meaning as a description of a general trend.