It might also has something to do with the Qi standard.
"3.2.3 Alignment Aids
Alignment aids assist the mobile device user in finding the charging zone. At least one method should be utilized. Examples of these could be retention clips that hold the device while aligning the inductive coils, magnets, visual target zones, alignment lights or providing a clearly identified charging zone that has an array of transmitter coils or a self-aligning transmitter coil."
So if it is a flat charger with a single coil, LED light appears mandatory.
Besides, not wanting to use black tape or black marker sounds a bit unreasonable to me.