[citrin_ru]

Actually there is at least one more common media where we can freely choose between dark and light (at least in the last 100+ years) - guide signs on roads. Both options are common (e. g. white on green/blue and black on white). But even if there are studies showing which background is better for signs it is not necessary the same for a computer screen: road sign should be legible from a maximum distance under variety of conditions - from a sunny day to LED lighting at nigh or heavy rain. Legibility is the main design goal. Computers on other hand are usually used in an environment where we can control lighting to some degree and a distance is fixed. Legibility is important but comfort is important as well (choose of colors should minimize eye strain / fatigue in case if it can affect this).