Agree that 4 hours seems inadequate: our students would be getting 3/4 hours per module and be encouraged to make individual appointments at least twice per semester for advice and feedback.
But as for the workload, it would be far easier and less time consuming for me to deliver 12 hours of classroom teaching and test the students on what I taught than to teach for 3 hours/module and then have to support the students to write good essays.
As for what they get out of it:
what a conscientious student who makes the most of his/her opportunities will learn from me (through seminars, email tuition, individual tuition by appointment, feedback on essays, material put up on blackboard etc etc) is:
how to work through large quantities of material
how to come up with good questions to ask of that material
how to organise their questions
how to search the material to find answers
how write their results up into good interesting prose
This presupposes that they have the time to try and make mistakes and have them assessed and try again. That would be a lot of training for one employer to offer.
Dh works in an area where about half the workers are university graduates and the other half are trained on the job. While there is no difference when they are out dealing with customers, back in the office it is invariably the graduates who end up doing the writing up. It is far harder for his boss to find enough work to do for those people who did not come to the job with any previous writing training.