It's tautological it the number of such minors is allowed to be zero, so by the maxim of relevance he probably meant to suggest it is not negligible -- but not necessarily also that it is close to 50%, especially not 50% among the general population rather than just 50% among the children of the kind of people he is talking to and/or about.
1 is irrelevant to autotrophs (e.g. cyanobacteria), who can synthesize their own food from achiral CO2 using sunlight; 2 is pretty much guaranteed if it's the only mirror life form in the ecosystem; 3 is obvious if it's the mirror image of an already existing life form; and it doesn't have to do 4 and 5 to achieve 6 (even a mirror cyanobacterium not otherwise interacting with non-mirror life would keep replicating and replicating exponentially until the biosphere runs out of CO2 or whichever other achiral nutrient turns out to be the limiting factor)
True, their impact on daily life isn’t necessarily obvious if you’re living in a superpower protected by its nuclear umbrella (someone in Ukraine might feel differently).
Is nuclear deterrence actually still a thing at all? Has any conflict in the past quarter century or so played out any differently than would have if on 1 January 2000 aliens had permanently taken away humanity's ability to use nuclear weapons?
How come B&N can ship to a ton of different countries including San Marino and the Vatican but not Italy???