My rangehood has a light and a three speed fan. There's a red warning light to show that the light is on (when that is rather obvious) but not a warning light to show that the fan is on. The fan on low speed is extremely quiet so a warning light would be useful.

All of my portable heaters have a warning light to show when it is consuming power, but the light goes off when the thermostat turns the heater off. I'd rather the light stayed on if the heater is switched on.

Is there something wrong with my logic?

My ceramic top stove works correctly - there is a warning light if the element is switched on or it is off but is hot.