The নেকড়ে-মানুষ don't like the Cullens because as werewolves/shapeshifters, they have an intrinsic animosity towards all vampires. They smell vampiric venom and instantly think "enemy". Even though the Cullens don't hunt humans, the নেকড়ে-মানুষ think of them sort of like a ticking time bomb. The নেকড়ে-মানুষ who don't like being নেকড়ে-মানুষ also blame the Cullens' presence for triggering their phasing and the negative effect that's had on their lives.
The Cullens mainly dislike the নেকড়ে-মানুষ because they're picking up on this animosity and reciprocating it. They also feel that the নেকড়ে-মানুষ smell weird - kind of like a wet dog smell - and they worry about নেকড়ে-মানুষ being a danger to Bella because of how they can't always control their phasing when they're new to being a werewolf.
