We need the .bashrc in order to properly change the bash prompt once changed into the image.

For example, here's the fedora:20 image:

-bash-4.2# docker run -it fedora:20 bash
[root@845950cd95f1 /]# cat /etc/fedora-release
Fedora release 20 (Heisenbug)
[root@845950cd95f1 /]# rpm -qf /root/.bashrc
rootfiles-8.1-16.fc20.noarch

For example, here's the fedora:latest image:

-bash-4.2# docker run -it fedora:latest bash
bash-4.3# rpm -qf /root/.bashrc
error: file /root/.bashrc: No such file or directory