>This is a very HN comment, because it ignores that a lot of people are paid for being physically present somewhere (not for their output).

Are you saying you think most people on HN do piecework? Because I sort of took for granted they were salaried.

At any rate, different companies within an industry area can be quite different.

I have had jobs involving programming that were:

  - salaried
  - hourly, with overtime
  - required time entry of billable/nonbillable projects worked on in 15 or 6 minute increments
  - required using a time clock (but not intraday time entry)
  - union
  - non-union

Only the time clock one (salaried, non-union) was primarily focused on "butts in seats". They also had something in the orientation about sleeping at your desk not being allowed.