I don't wonder why e.g. philips isn't too keen of LEDs as a general lighting...they sell lightbulbs, CFL and HID, which need replacement...over and over again. Other industries don't switch over because of high initial cost (lose money now, stocks go down, unhappy stock owners, big no-no).
The initial cost is the same problem that home growers have isn't it? So there is a bit more to it than just "they don't use it, it can't be good."

It has been done here with a couple of mistakes (no training, "killed" LED plant with HPS harvest water shortage?), but still.