because the market is flooded with CHEAP led sources.... almost comparable to HID pnp kits (on a smaller scale than leds) that come from China vs. quality real ones from Japan or Germanyon paper, LEDs sound great, durable and spelling the end to incandescents .... but with no regulation, no one keeping tabs on where mnftr's source LEDs for their applications in lamps, how is a LED that fails way under the stated time, sometimes within a year or less better than an incandescent that last 3-5-7 years..in the case of my Mercedes, all stock bulbs , not one has ever burned out...15 yrs old, ive only added bulb grease to them and that was about 8 years ago.Quality LEDs>Incandescents (Sylvannia, etc etc.) but there are so many variables and applications which can turn the tables and argument for or against them ; either as a factor of cost, safety, longevity (which is part of safety too , imho)