Motivation for K53: You need to be aware of your surroundings when you drive (situational awareness).
Implementation of K53: You move your head from side to side to satisfy examiners. Your face is pointed towards the blind spot but you aren't actually registering. When I did a couple of lessons for k53 with an instructor, I noticed afterwards that he never mentioned what sort of things I was checking for when I looked at my blind spot. No insight into the situation whatsoever.
In many ways I think the only way you're going to learn to drive is by driving, contrary to what
@SauRoNZA asserts. That being said however - the Finnish model, where children in school are taught about car control and that kind of thing on dedicated tracks - there could be value in that. I recently had to teach someone to drive and the problem was that they were learning two things at once - car control, and situational awareness / how other idiots on the road behave. It can be traumatising for a young person to have to figure out why the car is stalling so easily on an uphill, while there are impatient drivers hooting and zooming past. So a 2-stage model, if you like, where people can learn the basics of car control, how not to stall, emergency braking, and yes - parking - away from normal traffic can have value. But you'd still need actual experience on the road to be able to drive properly around other drivers.
When I learned to drive, I had been on the roads for years already with my bicycle, so I had a solid idea of the road rules and how motorists behave in traffic. So I learned car control on deserted streets and parking areas, and didn't have much hassle adjusting to actual traffic. But recently, in Cape Town's Southern Suburbs, finding empty streets for my student to practise on was a severe challenge. Came right eventually, but it took months and many tears (and yes a few scratches on the car but fortunately it was a cheap one bought for the purpose. No one else's car was harmed, just the side of my garage...).