Because they are always happy to see me. After work, whether they are foraging in the woods in the front yard or in the backyard in the woods somewhere, as soon as they see me they come running and begin talking to me telling me about the events of their day. They are simple joy.
When 3 standard brown hybrid chicks turned up one day about 3 years ago I had no idea how attached to chickens I would become in a way that's different from other pets I've had. Had never had birds before.
They seem to genuinely appreciate the benefits of being domestic but at the same time are a feathers breadth from being wild. Totally 'chicken' in their behaviour and sort of interestingly prehistoric but each with a character to get to know.
So funny!
They have practical needs but otherwise are completely undemanding and unassuming. (not to say they wont mob you to get something tasty!)
I love them very much!