Many people likes animals. Most of those same people eats Chicken,Mutton,Fish,Beef...so on....

So,Why many of those people who likes animals didn't thought that eating some animals is wrong ?

The same people who gets worried and angry when animals are being killed by poachers...but yet they eat chicken,mutton,beef,fish..so on.......

What is the difference ?

I mean...why some animals have to be killed and eaten by humans ?

Why can't these people who loves animals be Vegetarians ?