Chickens can live strong, healthy lives if they are taken care of. I have a hen called Bugger that's 6 years old and still begs for bugs if I'm digging. Chickens can catch diseases that make them weak and it can spread to other chickens but they don't just gorw up weak. Maybe some chick that lived through an illness but not all chickens are weak. Yes, all chickens get weak at some point but don't people do too? Weakness happens with age and sickness but most don't live their lives weak exept a rare few. As long as they are raised with care and love chickens can live good lives. You shouldn't get discouraged by 1 bad situation with chickens. It's like saying if you and your dad fought a lot that he'd throw you out because you just fight with him too much.If you don't get chickens fine, but at least learn that they can live very healthy for many years.