As I say, they have an operating window that's temperature sensitive. But, recognise that, drive accordingly with finesse and not a problem.
Corsa's are clearly not intended as a year round tyre, but the context of thread, to my eyes, is more about idiotic driving and less about tyres.
I can drive an Exige with Corsa's in sub 10 degree temperatures (sometimes combined with wet roads) and not get close to a dangerous situation. Not that that's what it's designed for, but the point is about the driver adjusting to conditions and available grip.
Would I drive with Corsa's in the snow or sub zero temps...no, not by choice at least. But I'd envisage most people that have a high performance car with sticky tyres have at least one, if not multiple alternative cars for more routine use in any case. Nothing wrong with the tyre's per se.
I think we're saying broadly the same thing, the only difference is, I think it's ultimately the driver that determines whether the car is driven within safe limits.