As much as we criticize them for what we see as poor UI and UX they have data supporting their decisions. So long as it drives more revenue they consider it positive.
The data might also settle on local maximums.
I mean consider a simple sort by rating. It's an explicitly exposed, well test feature. It may behave as designed, and may behave in a way that maximizes profits, but it does NOT behave the way a user expects it to behave nor would prefer it behave.
User experience designers should be ethically bound to do no harm to the user like doctors are bound by the Hippocratic Oath.