People may not like that feature (I sure don't), but I would bet a decent sum that feature didn't drive increases in negative metrics like churn, and increased positive metrics like hours watched, perhaps by causing people to scroll through more of the library faster, or perhaps drawing people in with the previews. Or maybe they just saw in improvement in a non-core metric like "distance scrolled" with no other negative effects and said, "meh, ship it". Both seem likely.

Of course this is the danger of any sort of behavioral metric driven optimization strategy - you may trade negative customer sentiment for positive business outcomes. That's where the real decision making comes about, i.e. are you willing to make that trade? It seems that in this case, Netflix was.