How many light bulbs does it take to replace an engineer?
Seriously, I can't tell you the number of debates concerning light bulbs on products. Do they stay on, indicating the unit is in standby? Do they turn off even if the unit is still powered, but the outputs are muted? How many is enough? and the corollary of that question. What colors should they be and do the colors mean anything: red for warning or attention, blue for 'ok' and cool?
The first big disagreement came with the second iteration of our launch product, the phonostage. The original hadn't any power switch and, if it was plugged in, the light stayed on. When we built the stage into a bigger box we offered the luxury of an on/off switch–only it didn't turn power on or off. It merely switched the outputs. We insisted that power remain to keep it sounding good. But would extinguishing the front panel light in cadence with the switch be dishonest–since the light had always indicated power?
In the end, the light went on/off with the switch and few 'caught' us on it, but the debate was heated and long winded.
Today it is standard practice to switch the light even when power's present–and it almost always is–but back then it was 'ground breaking' when we made that decision.