Sympathetic Zombies

In lecture our professor pointed out that in I am legend and in Night of the Living Dead there is not much behind the the shift between human and zombie-monster-creature and that perhaps because of how vulnerable individuals are to becoming monsters are and how humans respond with nothing but hostility that these monsters deserve some sympathy or consideration beyond what they are usually given. In Warm Bodies we also have a sympathetic monster-zombie. Its funny to me that these considerations are being extended when as humans we often disregard other species almost entirely. It seems to me that these sympathies are probably because it is a human that is being transformed into a monster. If it were another species of animal I doubt that we would've considered sympathy for the fallen/converted. It really seems ridiculous to me to extend compassion to zombified humans when we often won't extend compassion to other humans, animals, or plants.
Especially in I am Legend the main justification for extending compassion was that the monsters were the majority. I don't believe that is a legitimate reason. The change in perspective makes it interesting though because the greater good is something I believe in. Cognizant fiends seem to me more deserving of sympathy than masses of fiends and masses of fiends that are deadly, like in Safety Word or Night of the Living Dead don't deserve sympathy because there is no chance for coexistence. The monsters and men must war.  My feelings don't change for Safety Word where its clear the monsters are still somewhat human beucase there is no desire nor possibility of coexistence.