I have said this in the past and been nailed by my opinion. Less traction in the front causes understeer which is the most predictable and correctable handling flaw. That is why cars have designed in understeer to begin with.
As far as providing poor handling characteristic in an emergency maneuver you are correct. A Viper with mismatched tires will have lessened handling capability and predictability than a Viper with new tires on it. But then how about that same mismatched tire Viper compared to a Ford Pinto with 10 year old tires on it. Which would you rather be in when in an emergency situation? The Viper with mismatched tires, no doubt. So are all cars with worse handling characteristics a hazard for the street. No. Just drive within the cars (and your own) capability and you will be fine. No one should be at 90% or anywhere close on the street anyway.
Well put.
I guess the part the irks me the most about the gloom and doom that is told about tires is, that someone will clearly state that their use of the car is not to push the limits but more like Sunday afternoon with the wife kinda stuff. The OP basically made that statement in his first post. And then what follows is advice that factors in nth degree performance driving characteristics and/or a ready preparedness state you must be in for virtually any and all road hazards that in reality are just as likely as death in a plane crash or earthquake.
If you state you're not performance driving the car, then you don't need performance driving advice. Heck, you think the OP would be caught dead in the rain in his pride and joy?
If you're a safe responsible driver, then you probably are at a very low percentage risk of being involved in an unexpected event. You can manage that. And the one that gets you? Well, it's your turn to have a crappy day and that's just your bad luck that is out of your control. Ship happens.
When I wear my back tires out I will only replace them and continue to drive sensibly with the 2 year old fronts. Intelligence works.