I haven't been watching anything for a couple of years because I have two children and that limits tv a lot. However, the recommendation system still sucks.

They haven't recommended me lockwood and co on Netflix, we stumbled on it because it was popular (and we binged watched it one night when both were asleep).

So I do think it sucks. Recommendation seems to consider similarity, but not "quality" : they give equal treatment to their products, and the consequence seems to be that they show often garbage mixed in with good stuff...