these novels have low rating... just because the readers found ML or FL was horribly unsuited to their taste. They hate protagonists being too cruel, dense, not showing PDA, not mushy-mushy, etc... in general, most of the low rating abandoned the time setting (usually ancient kingdom --which was, if you are not too much illiterate person, very much patriarchal and feudalistic. 

Some just got low rating because of scenes/arcs in it... those people who gave these kind of rating just tooo much. If you didn't like some novels because they did have certain thing, make sure you see their tags. Bad mouthing author for including r*pe in his/her novel without seeing the same tag is there, on top part of novel description on NU list. So funny, Some novels with abusive and r*pe in it got relatively hi rating just because vistim n perperator then become lover, all chummy, lovey-dowey.. etc. Duh.