Reducing speeds in some places makes sense, but in county roads out in the country, it just creates a reason for bottleneck, which clumps traffic together, making collisions more likely.
For example, a 4-lane road that I drive on to get to the city will usually have two cars in the front driving practically the same speed, and slower than the traffic behind them. To fix this situation, the car on the left should speed up and get over, so that traffic can flow around it and spread out. Unfortunately, there is so much educational focus and enforcement on speed limits that the driver on the left believes [s]he is driving correctly.
Naturally, a lone country road designed for speed is fine. It's when you've got a high speed road with lots of on-street parking and pedestrians right next to traffic, even house fronts, where you've got a major clash of functionalities and a safety problem.
For example, a 4-lane road that I drive on to get to the city will usually have two cars in the front driving practically the same speed, and slower than the traffic behind them. To fix this situation, the car on the left should speed up and get over, so that traffic can flow around it and spread out. Unfortunately, there is so much educational focus and enforcement on speed limits that the driver on the left believes [s]he is driving correctly.