You're right, I should have mentioned that, as I actually had a similar experience. A lot of the comments I received were also along the lines of "that's great" (when I knew it wasn't and I was actually looking forward to some constructive criticism from someone better than me) or, as you mentioned, the classic "I don't know enough to help you".

Paying for qualified feedback would have made it better, although I still felt like I took a lot away from the taught content.