Indeed, every silly rule which draws upon it a just derision and universal flouting tends to undermine the general willingness to accept other, more justifiable and necessary rules. Very, very few people, as your poll shows, regard many of the speed limits to be reasonable or just. Therefore, they treat the business of vehicle speed as a contest with a capricious or malevolent enemy.
Radar detectors are simply a way of improving their odds of winning that contest more often.
It's NOT moral but LESS illegal in most places to drive at 40 mph through a school zone when the kids are getting out and cars are stopping and doors are opening and kids are dashing from all directions. Most of the time, it's just a traffic violation. There's a difference in both kind and degree. In the spirit of Tommy's Rant, the problem is even more profound. An intelligently conceived relationship between the moral citizen and the society to which he belongs would place the primary responsibility on the conscience of the individual and establish rules only as necessary to achieve the goals around which that society is organized.