I worked in Emergency Response for over 10 years, as a Tow Truck Driver. I have seen & cleaned up more fatal accidents then I care to remember.
With that said, I want to say that a bad driver is a bad driver whether or not they choose to use a radar detector. The same goes for good drivers.
SA is key. For me, where I live (between SF & Sacramento) the type of radar I can expect to come accross depends on where I'm driving. Inside the city limits of any of the towns in my area, you will find an extremely active revenue generating force of motorcycle cops armed with Radar. The cops in my town used to use on/off guns which I thought were tuff to detect. They just recently switched to a solid mounted unit which they can use while in motion.
The CHP uses Lidar on I-80 in my area, but not very often at all. Most speed enforcement on I-80 between SF & Nevada is done by Visual, Either from cops hiding at onramps, or by aircraft(very very very popular east of Sac). The CHP uses Radar on rural hiways, but interstate enforcement is mostly Mk 1 eyeball.
I agree that radar is more commonly used to generate revenue than to promote safety. I am a very safe driver, I use a detector, it has saved me a couple times, Its a Bel. I dont get alot of false alarms, & it picks up my local motor patrol well before my eyes do.
When driving on the highways I forget I have it, use my training & trust my instinct. If it goes off while im on the highway, I still slow down to find out why

Anton