The idea
Abolish them all, accept that some people are better able to drive carefully at whatever speed than others, the only time when people need to get points on their licence is when their driving could be argued to constitute a risk to other road users.
Why is it important?
There's roads with 30mph limits here that could safely be 60mph, and the other way round, speed limits applied to roads are not making sense anymore. Any driver should be able to judge the road conditions and drive at the speed he/she sees as appropriate. This will save the police time going after people driving a few mph over the speed limit.