You have the option of not buying it.
I am currently taking that option, and it will continue to lessen my interest in purchasing the system until they provide the option to dim/disable it.
By all means, force it on when required. I really enjoyed the Move on PS3 - the glowing sphere was annoying, but I accepted it as a necessary part of the technology, so I did my best to ignore it. I always turned off the Move controller immediately after I was finished to be rid of the distracting light when playing other games. The PS4 on the other hand, rarely uses the light for tracking, yet it insists on glowing all the time. It is not quite as bad as the Move's sphere, being only on the one side of the controller, angled away from glaring into your face, but it's still very bright for tracking purposes just like the Move controller. But this is no alternate motion controller. This is the
main controller, which fails to justify the glow the vast majority of the time, therefore it should have the option to be disabled (or at the very least, dimmed) until it is required for tracking again.