The only way any of this works is, if it can be guaranteed that there's almost a zero percent chance that someone infected enters the pitch and the surrounding area. If that can be achieved, with extensive testing and some social distancing measures in place, that would effectively eliminate the need to quarantine the entire team if one player is infected. Is this possible? Probably. Is it viable? I don't know, probably not at this point in time.
Either way it doesn't matter to my argument, because I didn't compare COVID-19 to injuries, I didn't at all express an opinion about the viability of the league returning or about any moral implications of keeping the players safe/unsafe. I specifically answered the question "Should they play without them - is that fair?", with the preface, that in isolation, playing with less than a full squad of players is completely fair and quite usual, but this doesn't necessarily mean that it should happen in this particular situation.
I am disputing this one particular point in his argument, that is completely nonsensical, with or without context. Players missing games is not unfair. The idea is, if you're completely convinced that only your way of thinking is correct and there's no debate to had, you should be able to prove that with solid, bulletproof, thought-out arguments and not pile on weaker ones with the hope that it makes your stance look stronger.