Um, what. I'm not sure you understand how R0 works, nor do you understand the point I was arguing. An acceptable level is a persistent value less than 1, but preferably much lower.
There's risks outside of infectious disease modeling. I'm not sure you understand the counterpoint they were making.
Because their question is a strawman towards something I wasn't attempting to understand. I can see where they're coming from with their question, but that's a whole different discussion. Like, if you want to have a discussion about why me riding a motorcycle is dangerous to myself and others, let's do that. But it's a different question and not relevant to a pandemic.