I've only taken a couple courses from one of these mini-degrees. I did feel like the quality was iffy, but I don't feel like I've seen enough to make a call on whether the problem was the instructor or the mini-degree.
The main problem was that the course was unfocused and rushed. It felt like the instructor was trying to touch on every single thing a person might learn over the course of a graduate level course. But since the class was shorter both in terms of number of weeks and time students could be expected to spend on any one week, it just resulted in a lot of very shallow treatment of an immense number of topics. Some lectures were barely more than a recitation of paper titles.
The main problem was that the course was unfocused and rushed. It felt like the instructor was trying to touch on every single thing a person might learn over the course of a graduate level course. But since the class was shorter both in terms of number of weeks and time students could be expected to spend on any one week, it just resulted in a lot of very shallow treatment of an immense number of topics. Some lectures were barely more than a recitation of paper titles.