Its a well established trend. As LED wattage increases, the
efficiency drops. LEDs are slowly moving up the incandescent
light product line as LED efficiency at higher wattage gets
better. Currently, LEDs have not yet conquered the tens of
watts market. However some of those incandescent lamps are
replaced by LEDs when the LED's ten year plus reliability is
required. And yes, those high wattage LEDs also require well
designed heatsinks.

In earlier days - especially after that L-1011 crashed into
the Everglades - then LEDs replaced 327 incandescent bulbs.
Early LEDs to replace 327s cost maybe $100. As technology
advances, the price drops and LEDs get more efficient at
higher wattages. But currently the LED is not yet there to
replace an incandescent room light.

It is a well establish principle of consumer electronics.
The new product must provide a decade of improvement. Low
wattage LEDs accomplish that. High power LEDs currently do
not. Meanwhile a technology that originally predated Edison's
light bulb - fluorescent - does provide that necessary
advantage.

Another source of LEDs to replace any incandescent bulb -
and have been doing this for decades - is LEDtronics. For
further information, seek articles about LEDs from Electronic
Products.

wrote:
Two points.

1. If I understand the warning correctly, it applies to environmental
temperature, as well as temperature rise due to heat generated by the
bulb.

2. I agree with you that the LED bulbs SHOULD NOT generate sufficient
heat to explain significant temperature rise, but one still active from
the batch that contains the failed bulbs warms up enough to be felt by
touch of the glass bulb.