I think the idea is to make sure young people know what they are getting into before they commit to nursing as a career.
Though, of course, the majority of nurses do an excellent job, there have been too many instances of poor care, including Mid-Staffs, to be ignored.
I'm not sure the engineering analogy works. I've known a number of qualified engineers who didn't like the work and went into sales.
My perception is that nurses stick with the job even if they find they are not really suited to it. There seems to be a strong pressure not to waste all the time spent training.
Plus, of course, there is an element of thinking that time spent doing the basics will instil them as a habit. A bit like basic training for squaddies.