Why do Cornish X's look so roughed up all the time?

[Master Quaillius]

So recently I have been studying about chicken breeds and I found the Cornish cross. I took one look and noticed that either the feathers were missing, broken or dirty. Why is this so?
-Thanks in advance.

 

[Squishychicken]

They grow so fast that there feathers can't keep up...

 

[Master Quaillius]

Oh that makes a lot of sense. Thanks!