They are Coronaviruses and since "if it is a coronavirus, it's just a cold" is your idea they are just bad colds until you pick another new definition.You’re the one that brought polio into it sparklenuts. Not sure about MERs and SARS; have to look up their survivability rates and wether or not they are corona viruses. If I had the spare time I’d….not spend it doing that. You go do it. If you find some data that is relevant report back on it.
I brought polio in because you defined bad cold by the percent who survive - it's not my problem you didn't like what that implied.
Now you seem to be implying "if it kills people I don't care about (the elderly) then it doesn't really matter".
Which is fine - you can define "a bad cold" however you want for your political purposes.