I hear you , but let me respond to some points youmade:

Point #1: being an attentive, aware driver is A #1 in my book also. However these passive systems are there for the times when you least expect a problem. Nobody can predict when some life threatening situation will occurr at 60+ mph.

Response: Tha argument could be used to support a literally endless mandate for th adoption of every new device that could offer a theoretical reduction in risk. At some point, cost benefit comes into play - or should. And unlike, say, a "public accommodation" (which all of us are compelled to use and so have a legitimate reason to demand government require certainthings, etc.) a car is something we choose to buy because we wish - and we should not have to purchase things we don't wish to buy simply because some people (for example, those who favor air bags) think everyone should have them, too. This opens a real can of worms. For example, the max speed in this country is 80 mph (in TX) and it's demonstrably true that your risk of injury or death if involved in an accident at higher speeds is greater than at lower speeds. So - and very much like air bags/your argument - why shouldn't speed governers limiting top speeds to 80 mph be mandatory too? Think of the lives that could be saved. Etc.

Point #2 & #3: Air bags are expensive to replace - especially with a 7+ year older car. Yes this is true - however the protection they provide against death or significant injury - IMO - out weighs this concern.

Response: This is a personal value judgment; others (myself included) disagree. What makes your value judgment carry more weight than mine - when it's my life, my money that's at issue?

Point #4:I personally believe things like air bags ought to be optional equipment I completely disagree. The protection is there for the passengers and the general public. It's sorta like saying: I don't need circuit breakers in my home, cause I'm never going to have a short circuit.

Response: Again, a value judgment - and unlike breakers, there is no "public safety" issue involved, except in the most tangential (and socialist) sense. Whether I have an air bag or not doesn't affect the safety of other drivers; I am certainly no more able to control the car and so on, because the car has an air bag. And it is a fact that air bags, though they do save lives, also injure and even kill some drivers and passengers. Another very valid reason to support individual choice on the question.

Maybe you don't want air bags - but someone may hit you - at a high rate of speed - and perhaps a loved one - or a passenger could be killed, maimed, or seriosly injured, that could have been prevented by an air bag. It doesn't make sense for the owner of a car to decide the fate of their passengers!

Response - If the matter is of concern, then don't ride in a car without air bags. It is a personal choice - very much as it is a choice to ride in a high-performance sports car (or subcompact econo-car), both of which may pose more "risk" than a mid-sized sedan, etc.