As blunt as he is, he's right about humanity's relationship with other animals. Humans ultimately fear what they can't control, and they sooner try to destroy the unknown than coexist with it. Even some pet animals can challenge humans when driven to aggression, and it usually doesn't end well for them. It's just what nature has programmed into us. We still don't know for sure which side began hostilities but monsters and humans are clearly at war now, so it's warranted.
The discussion about the light is interesting. Maybe they're not influenced by light, but emotions perhaps? Dark environments without any light can make anyone feel uneasy, and hallucinations in dark places are a known self-preservation mechanism in the human brain. Maybe that instinctual fear draws monsters towards people, while confidence allows humans not to be seen as prey. Maybe a state of mind has adverse effects on monsters.
And yet, being blind, Hinata is happy despite living in perpetual darkness as long as Hakumei's doppelganger is by her side. Poetic.