I think humans are supposed to be like that. I'm sure you could do it if you really had to, but it is always hard. I had to cull a hen that had EYP last fall and I teared up every time I thought about her for weeks after.
I am a vegetarian, but I could even raise some meat birds for a neighbor or something. That is a great idea for all those die-hard girls that don't want to give up.