Your idea that safer cars yield less-safe drivers is actually not without merit. There’s an interesting book, Traffic by Tom Vanderbilt that you might find interesting. Or not - I tend to be more geeky than most But it does have several interviews with traffic engineers who explain that the safer we make a road, the more recklessly people drive on it because they feel safer, and the same applies to cars.
There’s a psychological concept that people are comfortable with a certain level of risk, and they’ll tend to adjust their behavior to get to that level. If they’re comfortable whizzing along at 90mph when it’s dry and sunny, they’ll slow down at night when it’s raining. If they’re comfortable doing 45mph in a car with a broken seat belt, they’ll speed up once they get the seat belt fixed.
The trouble is that people are not very good at making rational risk assessments unless they’ve been formally trained to do so. That’s why many people who drive are afraid of flying even though they’re far more likely to get hurt in a car, and it also explains why you see so many morons flying past at 60mph in a snow storm.
And so, in short, you’re most likely right that the safer we make roads and cars, the dumber the average person will drive.
However, that should not be taken as an argument to go back to driving Corvairs and Pintos. Modern safety systems are effective provided drivers do not adjust their speed to compensate, which means the real solution is in making the roads appear (but not actually be) less safe than they are today. For instance, if you make lanes narrower by widening the marking strips, cars will still have the same amount of room as they did before, but the driver will feel like there’s less room and will therefore go slower.