Following up further on the artist/painter reference. In this case you are working on canvas or paper and daylight is excellent for all image quality to a point. The paintings are generally viewed in galleries under spotlights though, so in my work as a fine artist, I used special color corrected spot lights when working at my easel, while still allowing some daylight in.
For architects today, I imagine the vast majority are working on computer monitors, not paper - monitors are a light source (and a little radiation). So the brightly lit office now has competing light sources - the office lighting and the monitor - sometimes too much light for a creative working 12+ hours in a day.
For image editors, an office must maintain a constant light level so that color correction etc. has highly consistent results - so the most likely and easiest light level to maintain 24 hours a day is a dimly lit office.