Se pare ca in sfarsit cei de la Sony au dezvaluit adevaratul motiv pt light bar -> Project Morpheus.

Sony caused a lot of fuss when it confirmed that there would be no way of turning off the DualShock 4's light bar (the tyranny!), but do you want to know why it was really on there? Because of Project Morpheus.
Jed Ashforth, Senior Designer at Sony Computer Entertainment Europe, told TechRadar that Sony's virtual reality superteam ensured the tracking light was put into the controller - though everyone had to keep quiet about its main purpose.
Inner Tron

"The tracking light… it was our department that said we need that on," said Ashforth. "It was for tracking for VR."
"And when all these things were coming out six months ago and everyone was going 'it's reflecting in my TV,' we were going 'oh no' because we couldn't tell anyone what it was for."