Because segmented lamps require a good bit of wiring to use (particularly if you want to put two on a single circuit with their decoders) the circuit that holds them can take quite a drain on FPS for many systems. Hiding the circuitry helps, but then the segmented display is no longer visible.
If the Tiny Segmented Lamps remained visible when a circuit is hidden, then they could still be used and keep FPS impact as low as possible.
Because segmented lamps require a good bit of wiring to use (particularly if you want to put two on a single circuit with their decoders) the circuit that holds them can take quite a drain on FPS for many systems. Hiding the circuitry helps, but then the segmented display is no longer visible.
If the Tiny Segmented Lamps remained visible when a circuit is hidden, then they could still be used and keep FPS impact as low as possible.