Landscape mode in Tablet is terrible

In Tablet landscape mode, I am unable to view the left menu and still be able to navigate the discussion body on the right. It gets greyed out and locked up. I am forced to make it full screen which makes it very unreadable because it is too wide to track a sentence. This is effectively a UI bug as far as I'm concerned.

Take the screenshot below.  I should be able to use the message body in this mode.  I should not be forced to make the message body the full width to use it.