Yup, I'm at t'other end of the spectrum to you too. Just can't understand how you can look at a creature and feel no empathy.
It just baffles (and scares) me. And if you have no empathy, can't we even rely on selfishness? Aside from all the reasons already listed, does it not make you wonder what eating something grown with unhappy, unhealthy hormones will do to you? I'm not even talking about all the crap they are given just to stay alive (did you know that not too long ago, little boys in HK started growing breasts? No one could figure out why until they looked at their diets. Chicken pumped full of hormones.), I'm talking about the stress hormones that the poor creatures must produce bucket loads of.
And if you can live with all of that, I've got one word for you.
Karma.