The description says:
“The CSS rules applied to the whole website will override the default stylesheets of your theme and plugins”
I think it is quite clear the plugin is not meant to work on admin pages.
Your rating is totally unjustified.
I agree that styling the dashboard is not what I would expect from the description. I also feel that to give it 1 single star because of this is just plain mean/malicious. I am going to try this plugin because I like the per post/per page idea.
OK, I have tried the plugin – I’m afraid it’s not for me, it could really do with some code-colouring, line numbering and a console font. Apart from that there is nothing wrong with it IMO. Cheers! 🙂