Employers have absolutely no idea how productive one programmer solving one problem on his own without interruption or distraction can be. Because yes I know the feeling really well but no this barely ever happens in my day job.
I'm working today (Sunday) so I can accomplish something for work. Most of my work occurs on the weekend, before I go to work, or after I get home. Yet I am at the office >40hrs/week. It's a madness that I cannot sustain. But yay, we are moving to a new facility with cubicles (I have an office now). I just don't expect any productivity to be possible anymore.