I agree to you but they often think they are paying for an entire work day of focused working. As to me, I actually find the idea of 8 hours (or even 6) of uninterrupted (even if we don't count bathroom and lunch breaks) focused working absurd. It would require taking meth or enormous will effort. To me it seems all the time of pure focused work (unless it requires almost no mental processing) per day can only add up to 4 hours or so. IIRC there even is a scientific paper supporting this.