"Should accept it"..
Excellent straw man. Really.
Nobody forces anybody to bend any law on the statute books, but I can pretty much guarantee everybody breaks at least one with alarming regularity. However, it's also known that there should be "shades of grey" and that prosecuting some things under certain circumstances are not actually to the benefit of the general public. So, they're not enforced, as there is no benefit to society for doing so. They're there so that when people blatantly abuse the system, you can pull them up and throw the book at them (Tax evasion for Al Capone?).
The main cause of accidents (from the reports taken) are lack of attention, or dangerous/careless driving. If you got a camera that would spot the lunatics on the roads (you know, the ones that overtake streams of traffic on a bend as they want to arrive somewhere 30 seconds earlier, or travel 10 cm from your rear bumper on the motorway because they want to go at 110mph rather than the 80-85 that most of the traffic is doing), I have the strong suspicion that nobody would bat an eyelid (and many would be strong advocates, with a strong statistical and scientific backing).
However, it's nice and easy to pick up on one (contributing, not primary causative) aspect, and come down hard on it. If it didn't produce so much revenue, I don't think it'd have taken off quite so much, but it has proven quite the cash cow, despite the placing regulations preventing them being placed in the positions that really cry out for them (you know, where people travel under the speed limit because, in their good judgement, the road simply won't be safe to use at the rated limit). Yes, it's the law, but slavish adherence and turning the world into black and white to justify adherence is really just laziness, or maybe not really understanding the real problems.