what is wrong with people

I don't understand what goes through people's minds sometimes, i mean regarding everything but for this entry regarding animals. Like we've had two strays come into the cat rescue (where i work) and they've been through a really rough time since their owners abandoned them. One has been ditched when there owners left and has been in a car accident since then. And the other stray was found eating paper because she was so hungry, she was left without food for weeks until she was just skin and bone. and we've had multiple cats come to board while there owners were 'on holiday' and then they've just never came to pick their cats up. Like how could you do that to an animal, how would those people feel if they were abandoned with no shelter, no food, and no company. I just can't comprehend why people can treat animals like this.