In practice though, aprentices are often seen as cheap labour and are not at all trained well, if the madter to the aprentice lacks time or is a drunkard or what have you.

Especially in the simpler of proffesions, I fail to grasp the difference to the british system. Surely you need and will receive training of some form as well if you start a job. Do the school hours make the difference here? I am not convinved, given a butcher with already 10 years of school experience will be taught and tested for cheap stuff like percentage calculation. OTH you can become sysadmin apprentice and won't need a uni-degree, which is nice i suppose, as you get certified to know the essentials.