@zerimas
It's because Uramichi, though fitter than likely most of us, is a character close to many adult readers. The inexorable soul-grinding pressures of your work environment. The mind-scrping banality of sociopath bosses. His deep-seated dread towards every new workday and incrementally-creeping self-loathing by the end of it is YOUR career.
We find a cold numbing comfort in his daily misadventures, and, sympathizing with a nervous chuckle of our own, feel a little of our own load shared away.